Patents by Inventor Mikiya Yamasaki

Mikiya Yamasaki 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: 8012630
    Abstract: A polymer electrolyte secondary cell that is superior in the cycle characteristic and security during cell overcharge is provided. The polymer electrolyte of the cell includes a non-aqueous solvent, a lithium salt, and a polymer. The non-aqueous solvent contains at least one of ethylene carbonate and propylene carbonate. The volume ratio (25° C., 1 atm) of the ethylene carbonate and the propylene carbonate combined to the non-aqueous solvent is equal to or more than 60%. The polymer is made of a copolymer having a monomer containing N,N-dimethyl acrylamide and a compound with three or more acrylate groups and/or methacrylate groups. The ratio of the compound to the total mass of the monomer is from 10 to 30 mass %. The ratio of the polymer to the polymer electrolyte is from 1.0 to 2.0 mass %.
    Type: Grant
    Filed: September 26, 2007
    Date of Patent: September 6, 2011
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Mikiya Yamasaki, Kentaro Takahashi
  • Publication number: 20080081255
    Abstract: A polymer electrolyte secondary cell that is superior in the cycle characteristic and security during cell overcharge is provided. The polymer electrolyte of the cell includes a non-aqueous solvent, a lithium salt, and a polymer. The non-aqueous solvent contains at least one of ethylene carbonate and propylene carbonate. The volume ratio (25° C., 1 atm) of the ethylene carbonate and the propylene carbonate combined to the non-aqueous solvent is equal to or more than 60%. The polymer is made of a copolymer having a monomer containing N,N-dimethyl acrylamide and a compound with three or more acrylate groups and/or methacrylate groups. The ratio of the compound to the total mass of the monomer is from 10 to 30 mass %. The ratio of the polymer to the polymer electrolyte is from 1.0 to 2.0 mass %.
    Type: Application
    Filed: September 26, 2007
    Publication date: April 3, 2008
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Mikiya YAMASAKI, Kentaro TAKAHASHI
  • Publication number: 20050069765
    Abstract: The present invention provides a non-aqueous electrolyte cell that utilizes lithium manganese oxide, which is cheap, for the positive electrode active material and thus has improved high-temperature cycle characteristics. The non-aqueous electrolyte cell has a positive electrode including lithium manganese oxide as an active material, a negative electrode, and a polymer electrolyte. The polymer electrolyte is a polymerization of a prepolymer included in a prepolymer electrolyte that includes a non-aqueous solvent, an electrolyte salt, and the prepolymer. As the prepolymer, polyester acrylate and/or polyester methacrylate are used.
    Type: Application
    Filed: September 16, 2004
    Publication date: March 31, 2005
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventor: Mikiya Yamasaki
  • Patent number: 6623891
    Abstract: A polymer electrolyte battery having a high discharge capacity, a high mechanical strength, and a high heat resistance is provided. This polymer electrolyte battery includes: a polymer electrolyte layer 51 covering an edge face 20a of a positive electrode plate 20 and an edge part 40b of a porous membrane 40; a polymer electrolyte layer 52 covering an edge face 30a of a negative electrode plate 39 and an edge part 40c of the porous membrane 40; and a polymer electrolyte layer 53 covering an edge face 40a of the porous membrane 40 in a manner that connects the polymer electrolyte layer 51 with the polymer electrolyte layer 52.
    Type: Grant
    Filed: March 23, 2001
    Date of Patent: September 23, 2003
    Assignee: Sanyo Electric Co., Ltd.
    Inventor: Mikiya Yamasaki
  • Publication number: 20030148183
    Abstract: The inventors provide a non-aqueous electrolyte secondary battery in which the mass ratio of positive active materials, i.e., the mass ratio of lithium cobalt oxide to lithium manganese oxide is adjusted to improve both energy density and safety and in which a solvent containing ethylene carbonate (EC) and propylene carbonate (PC) is used so that the EC content and the PC content can be controlled to prevent swelling and improve both safety at overcharge and safety at a high temperature.
    Type: Application
    Filed: January 30, 2003
    Publication date: August 7, 2003
    Inventor: Mikiya Yamasaki
  • Publication number: 20010024756
    Abstract: A polymer electrolyte battery having a high discharge capacity, a high mechanical strength, and a high heat resistance is provided.
    Type: Application
    Filed: March 23, 2001
    Publication date: September 27, 2001
    Applicant: Sanyo Electric Co., Ltd.
    Inventor: Mikiya Yamasaki
  • Patent number: 5888671
    Abstract: The present invention is directed to a non-aqueous electrolyte battery comprising an anode, a cathode using a carbon material, and a non-aqueous electrolytic solution, wherein the carbon material obtained by coating a core composed of graphitized carbon in which spacing (d.sub.002) of lattice planes (002) is in the range of 3.35 to 3.39 .ANG. and the length (Lc) of a crystallite in the direction of the c axis is not less than 1000 .ANG. with coating graphitized carbon in which spacing (d.sub.002) of lattice planes (002) is more than that in the graphitizing carbon and is in the range of 3.36 to 3.48 .ANG., the carbon material obtained by coating a core composed of graphitized carbon in which spacing (d.sub.002) of lattice planes (002) is in the range of 3.35 to 3.39 .ANG.
    Type: Grant
    Filed: April 3, 1997
    Date of Patent: March 30, 1999
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Mikiya Yamasaki, Toshiyuki Nohma, Koji Nishio, Yasuyuki Kusumoto, Yoshihiro Shoji
  • Patent number: 5721069
    Abstract: Disclosed is a nonaqueous electrolyte secondary battery including a negative electrode prepared by coating a substrate with a slurry comprising a carbon material, an alkali metal salt of carboxymethylcellulose, and a styrene-butadiene rubber and drying it, the alkali metal salt accounting for 0.5.about.2 weight % of the total weight of the carbon material, styrene-butadiene rubber, and CMC alkali metal salt. Because of the higher electrical conductivity of the CMC alkali metal salt used as the thickening agent than the conventional carboxymethylcellulose or its ammonium salt, the secondary battery of the invention including the above negative electrode has an excellent load characteristic.
    Type: Grant
    Filed: December 4, 1996
    Date of Patent: February 24, 1998
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yoshihiro Shoji, Yasuyuki Kusumoto, Mikiya Yamasaki, Toshiyuki Nohma, Koji Nishio
  • Patent number: 5443930
    Abstract: A nonaqueous electrolyte battery comprises a positive electrode comprising a mixture of manganese dioxide and a fluorinated graphite as a positive electrode active material, a negative electrode comprising lithium metal or a substance capable of occluding and discharging lithium ion as a negative electrode material, and a nonaqueous electrolyte, said fluorinated graphite being represented by the formula (CFx)n wherein 1.2.ltoreq..times..ltoreq.1.4 and contained in said mixture in a ratio by weight of 0.1 to 4%. This battery undergoes minimal self discharge and has excellent storage capability, since reaction products formed by reaction of manganese dioxide and the nonaqueous electrolyte used minimally react with lithium on the negative electrode side.
    Type: Grant
    Filed: August 2, 1994
    Date of Patent: August 22, 1995
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yoshihiro Shoji, Mikiya Yamasaki, Koji Nishio, Toshihiko Saito