Patents by Inventor Takahiko Honma

Takahiko Honma 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: 6306542
    Abstract: One of the most important subject of the present invention is to provide a new lithium manganese composite oxide which does not include the cobalt which is few as the resource and expensive. For the above purpose, a lithium manganese composite oxide for a lithium secondary battery cathode active material represented by a composition formula of Li1−x Ax MnO2 (A is an alkali metal except for Li:0<x<1) and having a layered structure with a rock salt type ordered cations is adopted. According to the lithium manganese composite oxide, the crystal structure is stabilized since the lithium site of the layered structure LiMnO2 is replaced by the atom of alkali metal element having larger ionic diameter than the lithium ion. Accordingly, not only large discharge capacity is maintained but the cycle characteristic is excellent. In addition, since the lithium manganese composite oxide does not include the cobalt, it can be manufactured in low cost.
    Type: Grant
    Filed: May 21, 1999
    Date of Patent: October 23, 2001
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Hideyuki Nakano, Yoshio Ukyo, Takahiko Honma