Abstract: Provided is a transition metal precursor comprising a composite transition metal compound represented by Formula 1, 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 the transition metals of 2 period in the Periodic Table of the Elements; and 0<x<0.5. The transition metal precursor in accordance with the present invention has an oxidation number of a transition metal approximate to an oxidation number of a transition metal of the lithium-transition metal composite oxide prepared therefrom. Therefore, when the lithium-transition metal composite oxide is prepared using such a precursor, an oxidation or reduction process for varying an oxidation number can be simplified, resulting in superior process efficiency.

Abstract: Disclosed is an anode active material including: a crystalline phase comprising Si and a Si-metal alloy; and an amorphous phase comprising Si and a Si-metal alloy, wherein the metal of the Si-metal alloy of the crystalline phase is the same as or different from the metal of the Si-metal alloy of the amorphous phase.

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: 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: Disclosed is a new compound semiconductor represented by the chemical formula: Bi1-x-yLnxMyCuOTe where Ln belongs to the lanthanoid series and is any one or more elements selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, M is any one or more elements selected from the group consisting of Ba, Sr, Ca, Mg, Cd, Hg, Sn, Pb, Mn, Ga, In, Tl, As and Sb, and 0<x<1, 0?y?1 and 0<x+y<1. The compound semiconductor can replace a conventional compound semiconductor or be used as a thermoelectric conversion device together with a conventional compound semiconductor.

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 is an ionic conductor comprising a metal composite oxide characterized by comprising oxygen defects and metal defects in a cryolite lattice. An electrochemical device comprising the ionic conductor is also disclosed. The metal composite oxide has an improved ion conductivity, because formation of an open space within a lattice is ensured by the defects of metal ion sites in the lattice. Therefore, the metal composite oxide is useful for an ionic conductor or an electrochemical device requiring ionic conductivity.

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: Provided is a precursor for the preparation of a lithium transition metal oxide that is used for the preparation of a lithium transition metal oxide as a cathode active material for a lithium secondary battery, through a reaction with a lithium-containing compound, wherein the precursor contains two or more transition metals, and sulfate ion (SO4)-containing salt ions derived from a transition metal salt for the preparation of the precursor have a content of 0.1 to 0.7% by weight, based on the total weight of the precursor.

Abstract: Disclosed is a new compound semiconductor represented by the chemical formula: Bi1-x-yLnxMyCuOTe where Ln belongs to the lanthanoid series and is any one or more elements selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, M is any one or more elements selected from the group consisting of Ba, Sr, Ca, Mg, Cd, Hg, Sn, Pb, Mn, Ga, In, Tl, As and Sb, and 0<x<1, 0?y?1 and 0<x+y<1. The compound semiconductor can replace a conventional compound semiconductor or be used as a thermoelectric conversion device together with a conventional compound semiconductor.

Abstract: Thermoelectric conversion materials, expressed by the following formula: Bi1-xMxCuwOa-yQ1yTeb-zQ2z. Here, M is at least one element selected from the group consisting of Ba, Sr, Ca, Mg, Cs, K, Na, Cd, Hg, Sn, Pb, Eu, Sm, Mn, Ga, In, Ti, As and Sb; Q1 and Q2 are at least one element selected from the group consisting of S, Se, As and Sb; x, y, z, w, a, and b are 0?x<1, 0<w?1, 0.2<a<4, 0?y<4, 0.2<b<4 and 0?z<4. These thermoelectric conversion materials may be used for thermoelectric conversion elements, where they may replace thermoelectric conversion materials in common use, or be used along with thermoelectric conversion materials in common use.

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 is a new thermoelectric conversion material represented by the chemical formula 1: Bi1?xCu1?yO1?zTe, where 0?x<1, 0?y<1, 0?z<1 and x+y+z>0. A thermoelectric conversion device using said thermoelectric conversion material has good energy conversion efficiency.

Abstract: Disclosed is a lithium secondary battery, which is low in capacity loss after overdischarge, having excellent capacity restorability after overdischarge and shows an effect of preventing a battery from swelling at a high temperature.

Abstract: Disclosed herein is an electrolyte for lithium secondary batteries comprising: a chelating agent, which forms complexes with transition metal ions in the battery, and at the same time does not react and coordinate with lithium ions; a non-aqueous solvent; and an electrolyte salt, as well as a lithium secondary battery comprising the electrolyte. The chelating agent, which is contained in the electrolyte for lithium secondary batteries, can suppress a side reaction in which transition metal ions are reduced and deposited as transition metals on the anode. Also, the chelating agent can suppress internal short-circuits in the battery and the resulting voltage drop of the battery and a reduction in the safety and performance of the battery, which can occur when transition metals are deposited on the anode.

Abstract: Disclosed herein is an electrolyte for lithium secondary batteries comprising: a chelating agent, which forms complexes with transition metal ions in the battery, and at the same time does not react and coordinate with lithium ions; a non-aqueous solvent; and an electrolyte salt, as well as a lithium secondary battery comprising the electrolyte. The chelating agent, which is contained in the electrolyte for lithium secondary batteries, can suppress a side reaction in which transition metal ions are reduced and deposited as transition metals on the anode. Also, the chelating agent can suppress internal short-circuits in the battery and the resulting voltage drop of the battery and a reduction in the safety and performance of the battery, which can occur when transition metals are deposited on the anode.

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 is a method for regulating terminal voltage of a cathode during overdischarge. Also disclosed is a lithium secondary battery, which is low in capacity loss after overdischarge, having excellent capacity restorability after overdischarge and shows an effect of preventing a battery from swelling at a high temperature.

Abstract: Disclosed is a novel strontium-lanthanum-tungsten-containing metal composite oxide. An ionic conductor comprising the metal composite oxide and an electrochemical device comprising the ionic conductor are also disclosed. The metal composite oxide has an improved ionic conductivity, because formation of an open space within a lattice is ensured by the defects of metal ion sites in the lattice. Therefore, the metal composite oxide is useful for an ionic conductor or an electrochemical device requiring ionic conductivity.

Abstract: Disclosed is a novel strontium-lanthanum-yttrium-containing metal composite oxide. An ionic conductor comprising the metal composite oxide and an electrochemical device comprising the ionic conductor are also disclosed. The metal composite oxide has an improved ionic conductivity, because formation of an open space within a lattice is ensured by the defects of metal ion sites in the lattice. Therefore, the metal composite oxide is useful for an ionic conductor or an electrochemical device requiring ionic conductivity.