Patents by Inventor Youngsun Choi

Youngsun Choi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8268198
    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.
    Type: Grant
    Filed: April 3, 2009
    Date of Patent: September 18, 2012
    Assignee: LG Chem, Ltd.
    Inventors: Ho Suk Shin, Sung kyun Chang, Hong-Kyu Park, Sinyoung Park, Youngsun Choi, Seung Tae Hong, Hyo-shik Kil
  • Publication number: 20120064395
    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.
    Type: Application
    Filed: November 22, 2011
    Publication date: March 15, 2012
    Inventors: Sung Kyun Chang, Hong-Kyu Park, Ho Suk Shin, Seung Tae Hong, Youngsun Choi
  • Publication number: 20120043499
    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.
    Type: Application
    Filed: April 2, 2009
    Publication date: February 23, 2012
    Applicant: LG CHEM, LTD.
    Inventors: Ho Suk Shin, Sung Kyun Chang, Hong-Kyu Park, Seung Tae Hong, Sinyoung Park, Youngsun Choi
  • Publication number: 20120012781
    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.
    Type: Application
    Filed: March 17, 2011
    Publication date: January 19, 2012
    Applicant: LG CHEM, LTD.
    Inventors: Sung Kyun CHANG, Hong-Kyu PARK, Ho Suk SHIN, Seung Tae HONG, Youngsun CHOI
  • Publication number: 20120012780
    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.
    Type: Application
    Filed: March 17, 2011
    Publication date: January 19, 2012
    Applicant: LG CHEM, LTD.
    Inventors: Sung Kyun CHANG, Hong-Kyu PARK, Ho Suk SHIN, Seung Tae HONG, Youngsun CHOI
  • Publication number: 20110195303
    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.
    Type: Application
    Filed: March 22, 2011
    Publication date: August 11, 2011
    Inventors: Sung Kyun CHANG, Hong-Kyu Park, Ho Suk Shin, Seung Tae Hong, Youngsun Choi
  • Patent number: 7935444
    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.
    Type: Grant
    Filed: September 23, 2009
    Date of Patent: May 3, 2011
    Assignee: LG Chem, Ltd.
    Inventors: Sung Kyun Chang, Hong-Kyu Park, Ho Suk Shin, Seung Tae Hong, Youngsun Choi
  • Publication number: 20110089367
    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.
    Type: Application
    Filed: April 3, 2009
    Publication date: April 21, 2011
    Applicant: LG CHEM, LTD.
    Inventors: Ho Suk Shin, Sung Kyun Chang, Hong-Kyu Park, Sinyoung Park, Youngsun Choi, Seung Tae Hong, Hyo-Shik Kil
  • Publication number: 20110079752
    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.
    Type: Application
    Filed: June 2, 2010
    Publication date: April 7, 2011
    Applicant: LG CHEM. LTD.
    Inventors: Sinyoung PARK, Sung kyun CHANG, Hong-Kyu PARK, Seung Tae HONG, Youngsun CHOI
  • Publication number: 20100148115
    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.
    Type: Application
    Filed: September 23, 2009
    Publication date: June 17, 2010
    Applicant: LG CHEM, LTD.
    Inventors: Sung Kyun Chang, Hong-Kyu Park, Ho Suk Shin, Seung Tae Hong, Youngsun Choi