Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery using the same, and more particularly, to a positive electrode active material that includes a lithium composite oxide comprising at least nickel and cobalt, and is capable of improving particle stability not only on the surface portion but also at the central portion of the lithium composite oxide due to the formation of a concentration gradient in which a cobalt concentration decreases from the surface portion to the central portion of the lithium composite oxide relative to the average radius of the lithium composite oxide to a predetermined thickness, a positive electrode comprising the positive electrode active material, and the lithium secondary battery using the positive electrode.

Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery including the same, and more particularly, to a positive electrode active material including a lithium composite oxide containing at least nickel and cobalt, wherein since the cobalt in the lithium composite oxide has a concentration gradient having at least different slopes from a surface portion toward a central portion, it is possible to improve the stability of particles not only in a surface portion of the lithium composite oxide but also in a central portion thereof, a positive electrode including the positive electrode active material, and a lithium secondary battery using the negative electrode.

Abstract: The present invention comprises, in lithium composite oxide particles, an overlithiated oxide having a layered crystal structure and represented by chemical formula 1 below, and comprises a lithium manganese oxide represented by chemical formula 2 below outside the lithium composite oxide particles, wherein the overlithiated oxide included in the particles and the lithium manganese oxide included outside the particles have different Li/IM values. [Chemical formula 1] rLi2MnO3·(1-r)LiaNixCoyMnzM11-(x+y+z)O2 (wherein, in chemical formula 1, 0<r?0.6, 0<a?1, 0?x?1, 0?y<1, 0?z<1, and 0<x+y+z?1, and M1 is at least any one selected from Na, K, Mg, Al, Fe, Cr, Y, Sn, Ti, B, P, Zr, Ru, Nb, W, Ba, Sr, La, Ga, Mg, Gd, Sin, Ca, Ce, Fe, Al, Ta, Mo, Se, Zn, Nb, Cu, in, S, B, and Bi) [Chemical formula 2] LibMnpOq (wherein, in chemical formula 2, 0.1?b/p?2.5 and 0<q?15).

Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery including the same, and more particularly, to a bimodal-type positive electrode active material including a first lithium composite oxide as a small particle and a second lithium composite oxide as a large particle, wherein the positive electrode active material may uniformly improve the particle stability of the small particle and the large particle by controlling a slope of a concentration gradient in which cobalt in the small particle and the large particle decreases from a surface portion toward a central portion, a positive electrode including the positive electrode active material, and a lithium secondary battery using the positive electrode.

Abstract: The present invention relates to a positive electrode active material having improved electrochemical characteristics and improved stability, and a lithium secondary battery using a positive electrode including the positive electrode active material, and more particularly, to a positive electrode active material which may prevent decreases in electrochemical characteristics and stability of the positive electrode active material, which are caused by Li impurities, in advance by controlling the content of the Li impurities remaining on the surface of the positive electrode active material without a washing process to reduce the amount of residual lithium present on the surface thereof, and a lithium secondary battery using a positive electrode containing the positive electrode active material.

Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery including the same, and more particularly, to a positive electrode active material including a lithium composite oxide containing at least nickel and cobalt, wherein since the cobalt in the lithium composite oxide has a concentration gradient having at least different slopes from a surface portion toward a central portion, it is possible to improve the stability of particles not only in a surface portion of the lithium composite oxide but also in a central portion thereof, a positive electrode including the positive electrode active material, and a lithium secondary battery using the negative electrode.

Abstract: The present invention relates to a positive electrode active material, and a lithium secondary battery comprising a positive electrode including the positive electrode active material.

Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery comprising the same, and more particularly, to a positive electrode active material which exhibit improved driving characteristics under high-voltage operating conditions through surface modification of a lithium transition metal oxide of a Mid-Ni type having a relatively low nickel content, and to a lithium secondary battery comprising the same.

Abstract: The present disclosure relates to a novel polycrystalline cathode active material, and more specifically, provides a novel polycrystalline cathode active material having an effect of improving lifetime characteristics while securing excellent output and capacity characteristics by determining an optimal size and number of primary particles and a size of secondary particles by utilizing peak intensities of an H2 phase and an H3 phase.

Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery comprising the same, and more particularly, to a positive electrode active material comprising a mid-Ni type lithium transition metal oxide having a relatively low nickel content, wherein the c-axis length of unit particles constituting the lithium transition metal oxide is increased to enhance the efficiency of reversible intercalation/deintercalation of lithium ions, thereby improving electrochemical characteristics, which are relatively insufficient compared to those of a high-Ni type lithium transition metal oxide having a relatively high nickel content, and to a lithium secondary battery comprising the same.

Abstract: The present disclosure relates to a positive electrode active material and a lithium secondary battery including the same, and more particularly, to a positive electrode active material and a lithium secondary battery including the same, in which electrochemical characteristics and stability are improved by removing lithium-containing impurities present on the surface of a lithium composite oxide without a washing process.

Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery comprising the same, and more particularly, to a positive electrode active material, in which, instead of coating the surface of a unit particle constituting a lithium transition metal oxide, a cobalt-enriched region in which the distribution of cobalt is concentrated is formed in a surface portion of the unit particle, thereby reducing conductivity variation between unit particles caused by the formation of a non-uniform coating layer and improving electrochemical properties, including capacity characteristic and rate characteristic, and to a lithium secondary battery comprising the same.

Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery comprising the same, and more particularly, to a positive electrode active material comprising a overlithiated lithium manganese-based oxide, wherein a coating layer comprising a crystalline phase and an amorphous phase is formed on the surface of the lithium manganese-based oxide, thereby alleviating elution of transition metals from the lithium manganese-based oxide and suppressing side reactions on the surface of the lithium manganese-based oxide, and to a lithium secondary battery comprising the same.

Abstract: The present invention relates to a cobalt-free positive electrode active material having improved thermal stability and electrochemical properties, and a lithium secondary battery using the same.

Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery including the same, and more particularly, to a bimodal-type positive electrode active material including a first lithium composite oxide as a small particle and a second lithium composite oxide as a large particle, wherein the positive electrode active material may uniformly improve the particle stability of the small particle and the large particle by controlling a slope of a concentration gradient in which cobalt in the small particle and the large particle decreases from a surface portion toward a central portion, a positive electrode including the positive electrode active material, and a lithium secondary battery using the positive electrode.

Abstract: The present invention relates to a positive electrode active material which is formed such that a lithium ion diffusion path in a lithium composite oxide constituting a positive electrode active material is directed to a specific crystal plane, and has improved electrochemical properties and stability by improving the growth of the crystal plane to which the lithium ion diffusion path is directed, and a lithium secondary battery using the same.

Abstract: The present disclosure relates to a positive electrode active material for a lithium secondary battery, and more particularly, to a positive electrode active material for a lithium secondary battery having excellent electrical conductivity and energy density, and to a positive electrode and a secondary battery comprising the same.

Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery comprising the same. More specifically, the present invention relates to a positive electrode active material comprising a lithium manganese oxide in which lithium and manganese are present in excess, having an improved energy density per unit volume, and a lithium secondary battery comprising the same, thereby exhibiting enhanced electrochemical characteristics.

Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery comprising the same. More specifically, the present invention relates to a positive electrode active material comprising a lithium transition metal oxide of a Mid-Ni type having a relatively low nickel content, in which the content of fine powder in the positive electrode active material is controlled and the particle size distribution of the lithium transition metal oxide included in the positive electrode active material is adjusted, thereby improving capacity and lifetime characteristics and providing enhanced operational properties at high voltage.

Abstract: A positive electrode active material for a secondary battery according to an embodiment of the present invention comprises a lithium composite oxide represented by chemical formula 1 below and containing a layer-structured lithium excess oxide, wherein the lithium composite oxide comprises a secondary particle; the secondary particle comprises at least one primary particle; the primary particle comprises at least one crystallite; at least any one selected from the secondary particle, the primary particle, and the crystallite comprises a core and a shell occupying at least a portion of the surface of the core; and when the crystal structure belonging to space group C2/m is designated as [C2/m], the crystal structure belonging to space group R-3m is designated as [R-3m], and the ratio of the crystal structure belonging to space group C2/m versus the crystal structure belonging to space group R-3m is designated as [C2/m]/[R-3m], the [C2/m]/[R-3m] of the core differs from that of the shell in the secondary partic