Abstract: In a focus control method of a spectroscopic measuring apparatus, the spectroscopic measuring apparatus having a first objective lens and a second objective lens equipped with a microsphere is provided. A sample is placed on a stage. A spectrum is obtained while moving the second objective lens vertically downward. A light intensity function that changes with a distance from a sample surface is obtained from the spectrum. A focal position of the second objective lens is determined from a threshold value of the light intensity function.

Abstract: Nonreciprocal optical transmission devices and optical apparatuses including the nonreciprocal optical transmission devices are provided. A nonreciprocal optical transmission device includes an optical input portion, an optical output portion, and an intermediate connecting portion interposed between the optical input portion and the optical output portion, and comprising optical waveguides. A complex refractive index of any one or any combination of the optical waveguides changes between the optical input portion and the optical output portion, and a transmission direction of light through the nonreciprocal optical transmission device is controlled by a change in the complex refractive index.

Abstract: Nonreciprocal optical transmission devices and optical apparatuses including the nonreciprocal optical transmission devices are provided. A nonreciprocal optical transmission device includes an optical input portion, an optical output portion, and an intermediate connecting portion interposed between the optical input portion and the optical output portion, and comprising optical waveguides. A complex refractive index of any one or any combination of the optical waveguides changes between the optical input portion and the optical output portion, and a transmission direction of light through the nonreciprocal optical transmission device is controlled by a change in the complex refractive index.

Abstract: Nonreciprocal optical transmission devices and optical apparatuses including the nonreciprocal optical transmission devices are provided. A nonreciprocal optical transmission device includes an optical input portion, an optical output portion, and an intermediate connecting portion interposed between the optical input portion and the optical output portion, and comprising optical waveguides. A complex refractive index of any one or any combination of the optical waveguides changes between the optical input portion and the optical output portion, and a transmission direction of light through the nonreciprocal optical transmission device is controlled by a change in the complex refractive index.

Abstract: Nonreciprocal optical transmission devices and optical apparatuses including the nonreciprocal optical transmission devices are provided. A nonreciprocal optical transmission device includes an optical input portion, an optical output portion, and an intermediate connecting portion interposed between the optical input portion and the optical output portion, and comprising optical waveguides. A complex refractive index of any one or any combination of the optical waveguides changes between the optical input portion and the optical output portion, and a transmission direction of light through the nonreciprocal optical transmission device is controlled by a change in the complex refractive index.

Abstract: Disclosed are a novel compound, a method for preparing the same, and a lithium secondary battery comprising the same. More specifically, disclosed are a compound in which five MO6 octahedrons are bonded to one another around one MO6 octahedron such that the MO6 octahedrons share a vertex, to form hollows and Li cations substituted instead of Na cations using an ion substitution method are present in the hollows, and a crystal structure thereof is not varied even upon intercalation and deintercalation of Li cations, a method for preparing the same, and a lithium secondary battery comprising the same as a cathode active material.

Abstract: Provided is a cathode active material which is lithium transition metal oxide having an ?-NaFeO2 layered crystal structure, wherein the transition metal is a blend of Ni and Mn, an average oxidation number of the transition metals except lithium is more than +3, and lithium transition metal oxide satisfies the Equation m(Ni)?m(Mn) (in which m (Ni) and m (Mn) represent an molar number of nickel and manganese, respectively). The lithium transition metal oxide has a uniform and stable layered structure through control of oxidation number of transition metals to a level higher than +3, thus advantageously exerting improved overall electrochemical properties including electric capacity, in particular, superior high-rate charge/discharge characteristics.

Abstract: Provided is an electrode active material comprising a nickel-based lithium transition metal oxide (LiMO2) wherein the nickel-based lithium transition metal oxide contains nickel (Ni) and at least one transition metal selected from the group consisting of manganese (Mn) and cobalt (Co), wherein the content of nickel is 50% or higher, based on the total weight of transition metals, and has a layered crystal structure and an average primary diameter of 3 ?m or higher, wherein the amount of Ni2+ taking the lithium site in the layered crystal structure is 5.0 atom % or less.

Abstract: Provided is an electrode active material comprising a nickel-based lithium transition metal oxide (LiMO2) wherein the nickel-based lithium transition metal oxide contains nickel (Ni) and at least one transition metal selected from the group consisting of manganese (Mn) and cobalt (Co), wherein the content of nickel is 50% or higher, based on the total weight of transition metals, and has a layered crystal structure and an average primary diameter of 3 ?m or higher, wherein the amount of Ni2+ taking the lithium site in the layered crystal structure is 5.0 atom % or less.

Abstract: Disclosed are a novel compound, a method for preparing the same, and a lithium secondary battery comprising the same. More specifically, disclosed are a compound in which five MO6 octahedrons are bonded to one another around one MO6 octahedron such that the MO6 octahedrons share a vertex, to form hollows and Li cations substituted instead of Na cations using an ion substitution method are present in the hollows, and a crystal structure thereof is not varied even upon intercalation and deintercalation of Li cations, a method for preparing the same, and a lithium secondary battery comprising the same as a cathode active material.

Abstract: Provided is an electrode active material comprising a nickel-based lithium transition metal oxide (LiMO2) wherein the nickel-based lithium transition metal oxide contains nickel (Ni) and at least one transition metal selected from the group consisting of manganese (Mn) and cobalt (Co), wherein the content of nickel is 50% or higher, based on the total weight of transition metals, and has a layered crystal structure and an average primary diameter of 3 ?m or higher, wherein the amount of Ni2+ taking the lithium site in the layered crystal structure is 5.0 atom % or less.

Abstract: Provided is an electrode active material comprising a nickel-based lithium transition metal oxide (LiMO2) wherein the nickel-based lithium transition metal oxide contains nickel (Ni) and at least one transition metal selected from the group consisting of manganese (Mn) and cobalt (Co), wherein the content of nickel is 50% or higher, based on the total weight of transition metals, and has a layered crystal structure and an average primary diameter of 3 ?m or higher, wherein the amount of Ni2+ taking the lithium site in the layered crystal structure is 5.0 atom % or less.

Abstract: Disclosed are a novel compound, a method for preparing the same, and a lithium secondary battery comprising the same. More specifically, disclosed are a compound in which five MO6 octahedrons are bonded to one another around one MO6 octahedron such that the MO6 octahedrons share a vertex, to form hollows and Li cations substituted instead of Na cations using an ion substitution method are present in the hollows, and a crystal structure thereof is not varied even upon intercalation and deintercalation of Li cations, a method for preparing the same, and a lithium secondary battery comprising the same as a cathode active material.

Abstract: Provided is an electrode active material comprising a nickel-based lithium transition metal oxide (LiMO2) wherein the nickel-based lithium transition metal oxide contains nickel (Ni) and at least one transition metal selected from the group consisting of manganese (Mn) and cobalt (Co), wherein the content of nickel is 50% or higher, based on the total weight of transition metals, and has a layered crystal structure and an average primary diameter of 3 ?m or higher, wherein the amount of Ni2+ taking the lithium site in the layered crystal structure is 5.0 atom % or less.

Abstract: Provided is a cathode active material which is lithium transition metal oxide having an ?-NaFeO2 layered crystal structure, wherein the transition metal is a blend of Ni and Mn, an average oxidation number of the transition metals except lithium is more than +3, and lithium transition metal oxide satisfies the Equation m(Ni)?m(Mn) (in which m (Ni) and m (Mn) represent an molar number of nickel and manganese, respectively). The lithium transition metal oxide has a uniform and stable layered structure through control of oxidation number of transition metals to a level higher than +3, thus advantageously exerting improved overall electrochemical properties including electric capacity, in particular, superior high-rate charge/discharge characteristics.

Abstract: Provided is a cathode active material which is lithium transition metal oxide having an ?-NaFeO2 layered crystal structure, wherein the transition metal is a blend of Ni and Mn, an average oxidation number of the transition metals except lithium is more than +3, and lithium transition metal oxide satisfies the Equation m(Ni)?m(Mn) (in which m (Ni) and m (Mn) represent an molar number of manganese and nickel, respectively). The lithium transition metal oxide has a uniform and stable layered structure through control of oxidation number of transition metals to a level higher than +3, thus advantageously exerting improved overall electrochemical properties including electric capacity, in particular, superior high-rate charge/discharge characteristics.

Abstract: Provided is a lithium transition metal oxide having an ?-NaFeO2 layered crystal structure, as a cathode active material for lithium secondary battery, wherein the transition metal includes a blend of Ni and Mn, an average oxidation number of the transition metals except lithium is more than +3, and the lithium transition metal oxide satisfies Equations 1 and 2 below: 1.0<m(Ni)/m(Mn)??(1) m(Ni2+)/m(Mn4+)<1??(2) wherein m(Ni)/m(Mn) represents a molar ratio of nickel to manganese and m(Ni2+)/m(Mn4+) represents a molar ratio of Ni2+ to Mn4+. The cathode active material of the present invention has a uniform and stable layered structure through control of oxidation number of transition metals to a level higher than +3, in contrast to conventional cathode active materials, thus advantageously exerting improved overall electrochemical properties including electric capacity, in particular, superior high-rate charge/discharge characteristics.

Abstract: Disclosed herein is a cathode active material for a lithium secondary battery, in particular, including a lithium transition metal oxide with a layered crystalline structure in which the transition metal includes a transition metal mixture of Ni, Mn and Co, and an average oxidation number of all transition metals other than lithium is more than +3, and specific conditions represented by the following formulae (1) and (2), 1.1<m(Ni)/m(Mn)<1.5 and 0.4<m(Ni2+)/m(Mn4+)<1, are satisfied. The inventive cathode active material has a more uniform and stable layered structure by controlling the oxidation number of transition metals contained in a transition metal oxide layer to form the layered structure, compared to conventional substances. Accordingly, the active material exhibits improved overall electrochemical characteristics including battery capacity and, in particular, excellent high rate charge-discharge features.

Abstract: Disclosed are a novel compound, a method for preparing the same, and a lithium secondary battery comprising the same. More specifically, disclosed are a compound in which five MO6 octahedrons are bonded to one another around one MO6 octahedron such that the MO6 octahedrons share a vertex, to form hollows and Li cations substituted instead of Na cations using an ion substitution method are present in the hollows, and a crystal structure thereof is not varied even upon intercalation and deintercalation of Li cations, a method for preparing the same, and a lithium secondary battery comprising the same as a cathode active material.

Abstract: Provided is a transition metal precursor comprising a composite transition metal compound represented by Formula I, as a transition metal precursor used in the preparation of a lithium-transition metal composite oxide: M(OH1?x)2??(1) wherein M is two or more selected from the group consisting of Ni, Co, Mn, Al, Cu, Fe, Mg, B, Cr and transition metals of period 2 in the Periodic Table of the Elements; and 0<x<0.5.