Patents by Inventor Masahisa Fujimoto

Masahisa Fujimoto 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: 20100248040
    Abstract: A non-aqueous electrolyte secondary battery is provided that has a high discharge capacity and in which the structure is stable even when lithium is extracted to a high potential so that good cycle performance can be obtained. A non-aqueous electrolyte secondary battery has a negative electrode, a non-aqueous electrolyte, and a positive electrode having a positive electrode active material comprising sodium oxide, characterized in that: the sodium oxide contains lithium; and the molar amount of the lithium is less than the molar amount of the sodium.
    Type: Application
    Filed: November 15, 2006
    Publication date: September 30, 2010
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Motoharu Saito, Hideyuki Koga, Katsutoshi Takeda, Masahisa Fujimoto
  • Publication number: 20100239912
    Abstract: A non-aqueous electrolyte secondary battery has a positive electrode containing a positive electrode active material containing a lithium-containing oxide active material, a negative electrode, and a non-aqueous electrolyte. The lithium-containing oxide active material is represented by the general formula LiaMgbMO2±?, where 0.65?a?1.05, 0<b?0.3, 0 ???0.3, and M is at least one of manganese and cobalt.
    Type: Application
    Filed: March 22, 2010
    Publication date: September 23, 2010
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Motoharu Saito, Sho Tsuruta, Masahisa Fujimoto
  • Patent number: 7794881
    Abstract: An electrode for a lithium battery having a thin film composed of active material capable of lithium storage and release, e.g., a microcrystalline or amorphous silicon thin film, provided on a current collector, the electrode being characterized in that a constituent of the current collector is diffused into the thin film.
    Type: Grant
    Filed: October 20, 2000
    Date of Patent: September 14, 2010
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Masahisa Fujimoto, Shin Fujitani, Masaki Shima, Hiromasa Yagi, Hisaki Tarui, Hiroshi Kurokawa, Shigeki Matsuta, Yoichi Domoto, Yoshio Kato, Hiroshi Nakajima, Hiroaki Ikeda, Kenji Asaoka, Ryuji Ohshita
  • Publication number: 20100173202
    Abstract: A positive electrode active material is formed of a lithium containing layered oxide. The lithium containing layered oxide contains either or both of LiANaBMnxCoyO2±? that belongs to a space group P63mc or LiANaBMnxCoyO2±? that belongs to a space group Cmca. The lithium containing layered oxide contains the LiANaBMnxCoyO2±? as a solid solution, a mixture or both of them. In the LiANaBMnxCoyO2±?, 0.5?A?1.2, 0<B?0.01, 0.40?x?0.55, 0.40?y?0.55, 0.80?x+y?1.10 and 0???0.3.
    Type: Application
    Filed: June 25, 2008
    Publication date: July 8, 2010
    Inventors: Motoharu Saito, Masahisa Fujimoto, Katsutoshi Takeda
  • Publication number: 20100129715
    Abstract: A positive electrode active material is made of sodium containing oxide. The sodium containing oxide contains NaALiBMO2±? that belongs to a space group P63/mmc of a hexagonal system, where the M includes at least one of manganese (Mn) and cobalt (Co). In the NaALiBMO2±?, the composition ratio A of sodium (Na) is not less than 0.5 and not more than 1.1, the composition ratio B of lithium (Li) is larger than 0 and not more than 0.3, and the ? is not less than 0 and not more than 0.3.
    Type: Application
    Filed: March 21, 2008
    Publication date: May 27, 2010
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Motoharu Saito, Katsutoshi Takeda, Masahisa Fujimoto, Hiroshi Sawada
  • Patent number: 7709151
    Abstract: As a positive electrode active material, a lithium transition metal complex oxide having a layered rock-salt structure containing lithium (Li) and containing magnesium atoms (Mg) substituted for part of lithium atoms (Li) is used. The lithium transition metal complex oxide is formed by chemical or electrochemical substitution of Mg atoms for part of Li atoms in LiCoO2, LiMnO2, LiFeO2, LiNiO2, or the like. A cell is prepared in which a negative electrode 2 and a positive electrode 1 including the lithium transition metal complex oxide (positive electrode active material) are disposed in a non-aqueous electrolyte 5 including a lithium salt, and part of Li in the lithium transition metal complex oxide is extracted by discharging the cell. Then, the electrolyte including Li is replaced with an electrolyte including Mg, and the cell is discharged, so that Mg atoms are substituted for the part of Li atoms in the lithium transition metal complex oxide.
    Type: Grant
    Filed: September 5, 2008
    Date of Patent: May 4, 2010
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Takao Inoue, Masahisa Fujimoto, Masaharu Itaya
  • Publication number: 20100104944
    Abstract: A mixed positive electrode active material is used. The mixed positive electrode active material is obtained by mixing a layered oxide whose initial charge-discharge efficiency when lithium metal is used for a counter electrode is less than 100% (hereinafter referred to as a first layered oxide) and a layered oxide whose initial charge-discharge efficiency is 100% or more (hereinafter referred to as a second layered oxide). Examples of the first layered oxide include Li1+aMnxCoyNizO2. A sodium oxide such as LiANaBMnXCoYNiZO2 other than a layered compound from which lithium is previously extracted by acid treatment or the like can be used as the second layered oxide whose initial charge-discharge efficiency is 100% or more. A layered oxide obtained by replacing (ion exchange) sodium in the foregoing LiANaBMnXCoYNiZO2 with lithium can be also used as the second layered oxide.
    Type: Application
    Filed: December 26, 2007
    Publication date: April 29, 2010
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Motoharu Saito, Hideyuki Koga, Katsutoshi Takeda, Hiroshi Sawada, Masahisa Fujimoto
  • Patent number: 7695868
    Abstract: The positive electrode active material of a positive electrode includes a sodium-containing transition metal oxide (NaaLibMxO2±?). The M includes at least two of manganese (Mn), iron (Fe), cobalt (Co), and nickel (Ni). For a negative electrode, a sodium metal or a metal that forms an alloy with sodium is used. A non-aqueous electrolyte produced by dissolving an electrolytic salt (sodium salt) in a non-aqueous solvent is used. Examples of the non-aqueous solvent may include a cyclic carbonate, a chain carbonate, esters, cyclic ethers, chain ethers, nitrites, amides and a combination thereof.
    Type: Grant
    Filed: March 19, 2007
    Date of Patent: April 13, 2010
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Takao Inoue, Motoharu Saito, Masahisa Fujimoto, Masaharu Itaya
  • Publication number: 20100081056
    Abstract: A positive electrode active material includes a manganese oxide containing lithium and at least one substance selected from the group consisting of sodium, potassium, and rubidium. The manganese oxide has a strongest peak in the range of 2?=42.0° to 46.0° and a second strongest peak in the range of 2?=64.0° to 66.0°, as determined by X-ray powder diffraction analysis (Cuk?) of the manganese oxide.
    Type: Application
    Filed: September 30, 2009
    Publication date: April 1, 2010
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Motoharu Saito, Masahisa Fujimoto
  • Patent number: 7655273
    Abstract: A method of manufacturing an electrode active material particle for a rechargeable battery wherein a layer of an active material capable of being alloyed with Li is formed on a surface of a metal particle incapable of being alloyed with Li and then a heat treatment is conducted to diffuse the active material into the metal particle so that the resulting active material particle has a concentration profile in which a concentration of a metal element of the metal particle decreases from an interior toward the surface.
    Type: Grant
    Filed: November 9, 2007
    Date of Patent: February 2, 2010
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Masahisa Fujimoto, Yasuyuki Kusumoto, Masahide Miyake, Hiroaki Ikeda, Shin Fujitani
  • Publication number: 20100015532
    Abstract: A rolled foil of surface roughened copper as thick as 26 ?m for example having a surface formed into an irregular shape with copper precipitated thereon by an electrolytic method is prepared as a negative electrode collector. Tin (Sn) or germanium (Ge) is deposited on the rolled foil described above, so that a negative electrode active material layer is formed. Note that the deposited tin or germanium is amorphous. The arithmetic mean roughness Ra in the surface-roughened rolled foil described above is preferably not less than 0.1 ?m nor more than 10 ?m. A non-aqueous electrolyte is produced by adding sodium hexafluorophosphate as an electrolyte salt in a concentration of 1 mol/l to a non-aqueous solvent produced by mixing ethylene carbonate and diethyl carbonate in the ratio of 50:50 by volume.
    Type: Application
    Filed: January 20, 2006
    Publication date: January 21, 2010
    Inventors: Takao Inoue, Kumiko Kanai, Masaharu Itaya, Masahisa Fujimoto
  • Publication number: 20100009254
    Abstract: An object of the invention is to provide an inexpensive non-aqueous electrolyte secondary battery that allows reversible charge and discharge to be carried out and can be used for a long period because of a stable non-aqueous electrolyte used therein. The invention provides a non-aqueous electrolyte secondary battery including a positive electrode including a positive electrode active material and capable of storing and releasing sodium, a negative electrode capable of storing and releasing sodium, and a non-aqueous electrolyte, and the positive electrode active material includes sodium, nickel, manganese, and a transition metal that can exist in a hexavalent state. An example of the transition metal that can exist in a hexavalent state may include tungsten (W). An example of the negative electrode may include a sodium metal capable of storing and releasing sodium ions.
    Type: Application
    Filed: September 4, 2006
    Publication date: January 14, 2010
    Inventors: Masaharu Itaya, Hideyuki Koga, Kumiko Kanai, Takao Inoue, Masahisa Fujimoto
  • Patent number: 7524583
    Abstract: A non-aqueous electrolyte secondary cell is provided with a positive electrode, a negative electrode, and a non-aqueous electrolyte solution, wherein said positive electrode comprises sulfur and said non-aqueous electrolyte solution comprises a room-temperature molten salt having a melting point of 60° C. or less.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: April 28, 2009
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Masahide Miyake, Masahisa Fujimoto, Hideyuki Koga, Hisaki Tarui, Shin Fujitani
  • Patent number: 7521152
    Abstract: Li2-xAxMO3 obtained by replacing lithium in Li2MO3 having a layered structure by an alkali metal having ion radius larger than that of lithium is used as a positive electrode active material. In this Li2-xAxMO3, x satisfies the relation 0<x?O.5, the above-mentioned A indicates the alkali metal having the ion radius larger than that of lithium (Li) (for example, sodium (Na) or potassium (K)) and M indicates a transition metal that can be tetravalent. Examples of the transition metal that can be tetravalent indicated by the above-mentioned M include manganese (Mn), molybdenum (Mo), titanium (Ti), platinum (Pt), iridium (Ir), ruthenium (Ru) and the like.
    Type: Grant
    Filed: September 20, 2006
    Date of Patent: April 21, 2009
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Katsutoshi Takeda, Hideyuki Koga, Hiroshi Sawada, Masahisa Fujimoto
  • Publication number: 20090061311
    Abstract: An object of the invention is to provide a non-aqueous electrolyte secondary battery that allows a good charge/discharge cycle characteristic to be obtained. The non-aqueous electrolyte secondary battery according to the invention includes a negative electrode containing silicon as a negative electrode active material, a positive electrode, and a non-aqueous electrolyte, the average particle size of the negative electrode active material is not less than 5 ?m nor more than 20 ?m, and the weight of the negative electrode active material is at least 10% of the weight of the non-aqueous electrolyte.
    Type: Application
    Filed: February 3, 2006
    Publication date: March 5, 2009
    Inventors: Masaharu Itaya, Atsushi Fukui, Shouichirou Sawa, Yasuyuki Kusumoto, Masahisa Fujimoto
  • Publication number: 20090053613
    Abstract: A material (hereinafter referred to as “positive electrode material”) including sodium manganate powder as a positive electrode active material, carbon black powder as a conductive agent, and polytetrafluoroethylene as a binder is prepared. The positive electrode material is mixed in an N-methylpyrrolidone solution to produce slurry as a positive electrode mixture. A working electrode is produced by applying the slurry on a positive electrode collector. A negative electrode containing tin or germanium is produced. The non-aqueous electrolyte is produced by adding sodium hexafluorophosphate as an electrolyte salt in a non-aqueous solvent produced by mixing ethylenecarbonate and diethyl carbonate.
    Type: Application
    Filed: January 20, 2006
    Publication date: February 26, 2009
    Inventors: Takao Inoue, Masahisa Fujimoto, Kumiko Kanai
  • Publication number: 20090011336
    Abstract: As a positive electrode active material, a lithium transition metal complex oxide having a layered rock-salt structure containing lithium (Li) and containing magnesium atoms (Mg) substituted for part of lithium atoms (Li) is used. The lithium transition metal complex oxide is formed by chemical or electrochemical substitution of Mg atoms for part of Li atoms in LiCoO2, LiMnO2, LiFeO2, LiNiO2, or the like. A cell is prepared in which a negative electrode 2 and a positive electrode 1 including the lithium transition metal complex oxide (positive electrode active material) are disposed in a non-aqueous electrolyte 5 including a lithium salt, and part of Li in the lithium transition metal complex oxide is extracted by discharging the cell. Then, the electrolyte including Li is replaced with an electrolyte including Mg, and the cell is discharged, so that Mg atoms are substituted for the part of Li atoms in the lithium transition metal complex oxide.
    Type: Application
    Filed: September 5, 2008
    Publication date: January 8, 2009
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Takao Inoue, Masahisa Fujimoto, Masaharu Itaya
  • Publication number: 20090011335
    Abstract: A high-capacity positive electrode active material is provided that enables a non-aqueous electrolyte secondary battery to have excellent load characteristics and high initial charge-discharge efficiency. A non-aqueous electrolyte secondary battery has a positive electrode, a negative electrode, and a non-aqueous electrolyte, and performs charge and discharge by transferring lithium ions between the positive electrode and the negative electrode. The positive electrode has a positive electrode mixture and a positive electrode current collector. The positive electrode mixture contains a positive electrode active material, a conductive agent, and a binder agent (binder). The positive electrode active material includes Li1+x?a(MnyM1?y)1?xO2±b, where 0<a<0.3, 0<b<0.1, 0<x<0.4, 0<y<1, and 0.95<1+x?a<1.15, and M is at least one transition metal other than manganese (Mn).
    Type: Application
    Filed: June 25, 2008
    Publication date: January 8, 2009
    Inventors: Katsutoshi Takeda, Motoharu Saito, Hiroshi Sawada, Masahisa Fujimoto
  • Publication number: 20080299463
    Abstract: A nonaqueous electrolyte secondary battery that even at high-rate discharge wherein discharge is carried out at relatively large current, can attain an increase of discharge capacity. There is provided a nonaqueous electrolyte secondary battery comprising positive electrode (2), the positive electrode (2) including a collector and, superimposed thereon, a mixture layer containing a positive electrode active material in which lithium iron phosphate (LiFePO4) is contained, a conductive agent and a binder, the mixture layer exhibiting a mixture packing density after electrode formation of ?1.7 g/cm3, and further comprising nonaqueous electrolyte (5) containing a solvent in which ethylene carbonate and a linear ether such as 1,2-dimethoxyethane are contained.
    Type: Application
    Filed: January 10, 2006
    Publication date: December 4, 2008
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Kazunori Donoue, Takao Inoue, Denis Yau Wai Yu, Masahisa Fujimoto
  • Publication number: 20080292959
    Abstract: An object of the invention is to provide a positive electrode of an inexpensive material capable of sufficiently storing and releasing ions, and another object is to provide an inexpensive non-aqueous electrolyte secondary battery that allows reversible charge and discharge to be carried out. The positive electrode according to the invention includes an oxide containing potassium and manganese, and the non-aqueous electrolyte secondary battery according to the invention includes a positive electrode, a negative electrode, and a non-aqueous electrolyte containing potassium ions. The positive electrode includes an oxide containing potassium and manganese.
    Type: Application
    Filed: January 20, 2006
    Publication date: November 27, 2008
    Inventors: Takao Inoue, Masahisa Fujimoto