Abstract: Provided are a mixed cathode active material having improved power characteristics and safety, and a lithium secondary battery including the same. More particularly, the present invention relates to a mixed cathode active material which may assist power in a low SOC range to widen an available state of charge (SOC) range and may simultaneously provide improved safety by blending substituted LFP, in which operating voltage is adjusted by substituting a portion of iron (Fe) with other elements such as titanium (Ti), in order to prevent a rapid increase in resistance of manganese (Mn)-rich having high capacity but low operating voltage in a low SOC range (e.g., a SOC range of 10% to 40%), and a lithium secondary battery including the mixed cathode active material.

Abstract: A mixed positive electrode active material comprising a lithium manganese oxide represented by following [Chemical Formula 1] and a second positive electrode active material represented by following [Chemical Formula 2], and a lithium secondary battery comprising the same are disclosed. aLi2MnO3.(1?a)LixMO2??[Chemical Formula 1] In [Chemical Formula 1], 0<a<1, 0.9?x?1.2, and M is at least one element selected from the group consisting of Al, Mg, Mn, Ni, Co, Cr, V and Fe. Li4-xMn5-2x-yCO3xMyO12??[Chemical Formula 2] In [Chemical Formula 2], 0<x<1.5, 0?y<0.5, and M is at least one of transition metal elements. By comprising Mn-rich and Co-doped Li4Mn5O12, a rapid output decrease at a low SOC section may be relaxed to enlarge an available SOC section. Improved output may be obtained throughout an entire SOC section when compared with a case using pure Li4Mn5O12.

Abstract: Disclosed are a cathode active material for lithium secondary batteries and a lithium secondary battery including the same and, more particularly, the present invention relates to a cathode active material for lithium secondary batteries that includes a mixture of an overlithiated transition metal oxide represented by Formula 1 below and a lithium composite transition metal oxide represented by Formula 2 below: Li1+aNibMncCo1-(a+b+c+d)MdO2-sAs??(1) LiNixMnyCo1-(x+y+z)M?zO2-tA?t??(2) wherein 0.1?a?0.2, 0.1?b?0.4, 0.3?c?0.7, 0?d?0.1, 0.5?x?0.8, 0.1?y?0.4, 0?z?0.1, 0?s<0.2, and 0?t<0.2; M and M? are each independently at least one divalent or trivalent metal; and A and A? are each independently at least one monovalent or divalent anion.

Abstract: Provided is a secondary battery comprising a positive electrode active material represented by the following Chemical Formula 1, Li{LiaMnxM1-a-x-yM?y}O2??[Chemical Formula 1] where 0<a?0.2, x>(1?a)/2, and 0<y<0.2(1?a), and M is simultaneously applied by any one element or two or more elements selected from the group consisting of group 3 and 4 elements, and M? is a metal having an ion diameter of 70 pm or more with an oxidation number of 4 as well as a six-coordinate octahedral structure (specifically, any one element or two or more elements selected from the group consisting of titanium (Ti), vanadium (V), and iron (Fe) are simultaneously applied). According to the present invention, a high capacity lithium secondary battery having improved safety and processability may be provided.

Abstract: Disclosed is a cathode active material including a lithium manganese-based oxide. The lithium manganese-based oxide has a spinel structure represented by Formula 1 below and high lithium ion diffusivity since (440) planes are predominantly formed in a crystal structure thereof. Li1+xMyMn2-x-yO4-zQz??(1) In Formula 1, 0?x?0.3, 0?y?1, and 0?z?1, M includes at least one element selected from the group consisting of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, Ti, and Bi, and Q includes at least one element selected from the group consisting of N, F, S, and Cl.

Abstract: The present disclosure provides a stack-folding type electrode assembly in which a plurality of full cells or bicells as unit cells is stacked on top of each other and surrounded by a second separator, each cell including a positive electrode, a negative electrode, and a first separator interposed between the positive electrode and the negative electrode, wherein a first binder is coated on at least a partial surface of the first separator, a second binder is coated on at least a partial surface of the second separator, and a content of the second binder is higher than a content of the first binder, to inhibit a loose phenomenon inside a battery, make the battery less prone to expansion, and have deformation resistance to an external impact.

Abstract: The present disclosure provides an electrode assembly comprising a plurality of unit cells, each unit cell having a full-cell or a bi-cell structure comprising a cathode, an anode, and a first separator interposed between the cathode and the anode, and the plurality of unit cells being stacked by surrounding each unit cell with a second separator, wherein the second separator has an average pore diameter (d2) larger than the average pore diameter (d1) of the first separator in the unit cells.

Abstract: A high capacity lithium secondary battery includes a lithium manganese oxide having a layered structure exhibiting a great irreversible capacity in the event of overcharging at a high voltage and a spinel-based lithium manganese oxide. Because it is activated at a high voltage of 4.45 V or higher based on a positive electrode potential, additional lithium for utilizing a 3V range of the spinel-based lithium manganese oxide can be provided and an even profile in the entire SOC area can be obtained. Because the lithium secondary battery includes the mixed positive electrode active material including the spinel-based lithium manganese oxide and the lithium manganese oxide having a layered structure, and is charged at a high voltage, its stability can be improved. Also, the high capacity battery having a large available SOC area and improved stability without causing an output shortage due to a rapid voltage drop in the SOC area can be implemented.

Abstract: Provided are a positive electrode active material for improving an output and a lithium secondary battery including the same. Particularly, graphite and conductive carbon which have shapes and sizes different from each other, may be simultaneously coated on a mixed positive electrode material of a 3-component system lithium-containing metal oxide having a layered structure and expressed as following Chemical Formula 1 and LiFePO4 having an olivine structure as an conductive material to improve high resistance occurrence and conductivity reduction phenomenon of a 3-component system lithium metal oxide due to a difference between particle sizes and surface areas of the 3-component system lithium-containing metal oxide and LiFePO4 olivine. Li1+aNixCoyMn1-x-yO2, 0?a<0.5, 0<x<1, 0<y<0.

Abstract: The present disclosure provides an electrode assembly comprising a plurality of unit cells, each unit cell having a full-cell or a bi-cell structure comprising a cathode, an anode, and a first separator interposed between the cathode and the anode, and the plurality of unit cells being stacked by surrounding each unit cell with a second separator, wherein the second separator has an average pore diameter (d2) larger than the average pore diameter (d1) of the first separator in the unit cells.

Abstract: An electrode assembly, comprises one or more first electrodes comprising a cathode; one or more second electrodes comprising an anode; and a separator sheet having a zigzag form interposed therebetween. The separator sheet comprises a first porous polymer substrate; a first coating layer formed on one surface of the first porous polymer substrate and comprising a polymer binder, the first coating layer being faced with the cathode; and a second coating layer formed on the other surface of the first porous polymer substrate and comprising a mixture a polymer binder and inorganic particles, the second coating layer being faced with the anode and having a composition, a thickness and a porosity different from those of the first porous coating layer. A separator has porous coating layers with a different composition, thickness or porosity formed on each surface thereof.

Abstract: A lithium secondary battery having improved output characteristics is provided. A high voltage mixed positive electrode active material has an even profile without causing a rapid voltage drop over the entire SOC area by improving a rapid voltage drop phenomenon occurring due to the difference between the operation voltages of mixed lithium transition metal oxides, and improves output characteristics at a low voltage. The lithium secondary battery includes the mixed positive electrode active material. In particular, the lithium secondary battery can sufficiently satisfy the required conditions such as output characteristics, capacity, stability, and the like, when it is used as a power source of a midsize or large device such as an electric vehicle.

Abstract: The present disclosure relates to a positive electrode for a lithium secondary battery including an electrode current collector, and a positive electrode active material layer coated on at least a part of the electrode current collector, wherein the positive electrode active material layer includes a manganese-based positive electrode active material, and a porosity is from 30% to 35%, to improve high-temperature storage characteristics and high-temperature cycle characteristics.

Abstract: An object of the present invention is a cathode active material including a lithium manganese-based oxide. The lithium manganese-based oxide has a spinel structure, exhibits core-shell phase transition by which phase transition of a crystal structure occurs from a cubic structure to a tetragonal structure in a direction from the surface of particles to the center of the particles during discharging to the 3V region, and includes a conductive material at the shell to improve electrical conductivity of the tetragonal structure.

Abstract: The present disclosure provides a stack-folding type electrode assembly in which a plurality of full cells or bicells as unit cells is stacked on top of each other and surrounded by a second separator, each cell including a positive electrode, a negative electrode, and a first separator interposed between the positive electrode and the negative electrode, wherein a first binder is coated on at least a partial surface of the first separator, a second binder is coated on at least a partial surface of the second separator, and a content of the second binder is higher than a content of the first binder, to inhibit a loose phenomenon inside a battery, make the battery less prone to expansion, and have deformation resistance to an external impact.

Abstract: Provided is a cathode active material including lithium manganese-based oxide, wherein the lithium manganese-based oxide has a layered crystal structure, has a content of manganese (Mn) greater than contents of other transition metal(s), includes 1 mole or more of lithium (Li) with respect to 1 mole of lithium transition metal oxide, has a plateau potential range in which lithium deintercalation as well as oxygen release occurs during initial charging in a high voltage range of 4.4 V or more, has domains included in the layered crystal structure exhibiting electrochemical activity due to a structural change in a potential range of 3.5 V or less after the initial charging, and includes conductive materials for improving electrical conductivity of the lithium manganese-based oxide in a potential range of 3.5 V or less after the initial charging.

Abstract: The present disclosure provides a method for preparing a lithium secondary battery by bringing a first cell using a first cathode active material of formula (I) Li(LixMy-y?M?y?)O2-zAz??(I) wherein, x, y, y?, and z satisfy 0<x<0.5, 0.6<y<1.1, 0?y?<0.2, and 0?z<0.2, M is any one selected from the group consisting of Mn, Ni, Co, Fe, Cr, V, Cu, Zn, and Ti, M? is any one selected from the group consisting of Al, Mg and B; and A is any one selected from the group consisting of F, S and N and a second cell using a second cathode active material being generally used into activation under different voltage conditions, and then electrically connecting the first cell and the second cell in the step of assembling unit cells; and a lithium secondary battery prepared from the method.

Abstract: The present disclosure provides a method for removing gases generated in a lithium secondary battery using a cathode active material of the following formula (I) Li(LixMy-y?M?y?)O2-zAz??(I) wherein, x, y, y?, and z satisfy 0<x<0.5, 0.6<y<1.1, 0?y?<0.2, and 0?z<0.2, M is any one selected from the group consisting of Mn, Ni, Co, Fe, Cr, V, Cu, Zn, and Ti, M? is any one selected from the group consisting of Al, Mg and B; and A is any one selected from the group consisting of F, S and N by carrying out two or more degassing steps under the conditions of above and below a voltage that the structural variation of the cathode active material occurs, thereby inducing a uniform initial reaction in a cathode and an anode to enhance the life time of the battery.

Abstract: The present disclosure refers to a cathode material composite having improved conductivity, and a cathode and electrochemical device having the cathode material composite. In accordance with one embodiment of the present disclosure, a conductive polymer is positioned on the surface of a shell present in the form of a tetragonal structure in the lithium manganese oxide, thereby enhancing electrical conductivity to be highly involved in reaction around 3V, and providing a conductive path to improve the capacity, life and rate characteristics of an electrochemical device.

Abstract: Disclosed are a cathode active material for lithium secondary batteries and a lithium secondary battery including the same and, more particularly, the present invention relates to a cathode active material for lithium secondary batteries that includes a mixture of an overlithiated transition metal oxide represented by Formula 1 below and a lithium composite transition metal oxide represented by Formula 2 below: Li1+aNibMncCo1-(a+b+c+d)MdO2-sAs??(1) LiNixMnyCo1-(x+y+z)M?zO2-tA?t??(2) wherein 0.1?a?0.2, 0.1?b?0.4, 0.3?c?0.7, 0?d?0.1, 0.5?x?0.8, 0.1?y?0.4, 0?z?0.1, 0?s?0.2, and 0?t?0.2; M and M? are each independently at least one divalent or trivalent metal; and A and A? are each independently at least one monovalent or divalent anion.