Lg Chem, Ltd

Hera Lee

Hong-Kyu Park

Sinyoung Park

Hyo-Shik Kil

Sung-Kyun Chang

Sung Kyun Chang

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 +3 or higher, and the lithium transition metal oxide satisfies Equations 1 and 2:1.0&#x3c;(Ni)/(Mn)&#x2003;&#x2003;(1)(Ni)/(Mn)&#x3c;1&#x2003;&#x2003;(2)wherein m(Ni)/m(Mn) represents a molar ratio of nickel to manganese and m (Ni)/m (Mn) represents a molar ratio of Nito Mn. 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.

Cathode active material for lithium secondary battery

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 +3 or higher, and the lithium transition metal oxide satisfies Equations 1 and 2:1.0&#x3c;(Ni)/(Mn)&#x2003;&#x2003;(1)(Ni)/(Mn)&#x3c;1&#x2003;&#x2003;(2)wherein m(Ni)/m(Mn) represents a molar ratio of nickel to manganese and m(Ni)/m(Mn) represents a molar ratio of Nito Mn. 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.

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 +3 or higher, 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.

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Daejeon, South Korea

Hera Lee