Lg Chem, Ltd

Lg Energy Solution, Ltd.

Youngsun Choi

Hong-Kyu Park

Sung Kyun Chang

Seung Tae Hong

Ho Seon Shin

Sinyoung Park

Seung-Tae Hong

YoungHwa Jung

Hyo-Shik Kil

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 MOoctahedrons are bonded to one another around one MOoctahedron such that the MOoctahedrons 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.

Compound, method for preparation of the same, and lithium secondary battery comprising the same

Provided is a cathode active material which is lithium transition metal oxide having an &#x3b1;-NaFeOlayered 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)&#x2267;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.

Cathode active material for lithium secondary battery

Provided is an electrode active material comprising a nickel-based lithium transition metal oxide (LiMO) 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 &#x3bc;m or higher, wherein the amount of Nitaking the lithium site in the layered crystal structure is 5.0 atom % or less.

Electrode active material for lithium secondary battery

Provided is a cathode active material which is lithium transition metal oxide having an &#x3b1;-NaFeOlayered 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)&#x2267;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.

Provided is a lithium transition metal oxide having an &#x3b1;-NaFeOlayered 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&#x3c;(Ni)/(Mn)&#x2003;&#x2003;(1)(Ni)/(Mn)&#x3c;1&#x2003;&#x2003;(2) 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.

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&#x3c;m(Ni)/m(Mn)&#x3c;1.5 and 0.4&#x3c;m(Ni)/m(Mn)&#x3c;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.

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(OH)&#x2003;&#x2003;(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&#x3c;x&#x3c;0.5.

Precursor for the preparation of a lithium composite transition metal oxide

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 (SO)-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.

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Daejeon, South Korea

Youngsun Choi