Patents by Inventor Kyou-Yoon Sheem

Kyou-Yoon Sheem 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).

  • Publication number: 20020039685
    Abstract: A negative active material for a lithium secondary battery includes a graphite-like carbon material having an intensity ratio I(110)/I(002) of an X-ray diffraction peak intensity I(002) at a (002) plane to an X-ray diffraction peak intensity I(110) at a (110) plane of less than 0.2. The negative active material prepared by dissolving a coar tar pitch or a petroleum pitch in an organic solvent to remove insoluble components therefrom, heat-treating the pitch at a temperature in the range of 400 to 450° C. for 4 hours or more under an inert atmosphere to thereby produce at least 50 weight percent of mesophase particles based on the pitch, coking the pitch including mesophase particles, carbonizing the coked pitch, pulverizing the carbonized pitch; and graphitizing the pulverized pitch.
    Type: Application
    Filed: March 10, 1999
    Publication date: April 4, 2002
    Inventors: WAN-UK CHOI, KYOU-YOON SHEEM, SANG-YOUNG YOON
  • Patent number: 6355377
    Abstract: A negative active material for a rechargeable lithium battery which exhibits good high-rate charge characteristics and cycle life characteristics. The active material includes a crystalline carbon core and a semi-crystalline carbon shell. The semi-crystalline carbon shell includes at least one element or a compound of at least two different types of elements and carbides thereof, and has a turbostratic or half onion-sheath. The compound includes only element. The element serves a graphitization catalyst and causes a change in a structure of surrounding carbon. In particular, the negative active material includes metal boride and metal carbide.
    Type: Grant
    Filed: September 22, 2000
    Date of Patent: March 12, 2002
    Assignee: Samsung SDI Co., Ltd.
    Inventors: Kyou-Yoon Sheem, Sang-Young Yoon, Wan-Uk Choi, Jae-Yul Ryu, Sang-Jin Kim
  • Publication number: 20020012845
    Abstract: The present invention relates to a negative active material for a rechargeable lithium battery and a method of preparing the same, said negative active material comprising crystalline carbon having a dispersed element serving as graphitization catalyst therein. Said negative active material for a rechargeable lithium battery is prepared by the steps of adding an element serving as a graphitization catalyst to a carbon precursor; coking the mixture by heat-treating at 300 to 600° C. carbonizing the cokes; and graphitizing the carbide at 2800 to 3000° C.
    Type: Application
    Filed: June 11, 2001
    Publication date: January 31, 2002
    Inventors: Wan-Uk Choi, Kyou-Yoon Sheem, Sang-Jin Kim, Jae-Yul Ryu, Sang-Young Yoon
  • Publication number: 20020006551
    Abstract: Disclosed is carbonaceous active material for a lithium-ion secondary battery. Conducting a differential thermal analysis on the carbonaceous active material results in the displaying of at least two exothermic peaks overlapping to form shoulders.
    Type: Application
    Filed: July 29, 1999
    Publication date: January 17, 2002
    Inventors: JAE-YUL RYU, SANG-YOUNG YOON, KYOU-YOON SHEEM, SANG-JIN KIM, WAN-UK CHOI
  • Publication number: 20010053743
    Abstract: Disclosed is a negative active material for a lithium secondary battery. The negative active material includes graphitized coke having a graphitization catalyst element and non-flat artificial graphite. The negative active material for a lithium secondary battery has good electrolyte-immersibility due to the gap between the graphite particles from graphitized coke having a graphitization catalyst element, and non-flat artificial graphite. Therefore, the present invention may provide a lithium secondary battery which has good high-rate capacity and initial efficiency.
    Type: Application
    Filed: May 9, 2001
    Publication date: December 20, 2001
    Inventors: Jae-Yul Ryu, Sang-Young Yoon, Wan-Uk Choi, Kyou-Yoon Sheem, Sang-Jin Kim