Patents by Inventor Yasuhiko Bito

Yasuhiko Bito 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: 20070048611
    Abstract: A non-aqueous electrolyte secondary battery including a positive electrode, a negative electrode, and a non-aqueous electrolyte. The positive electrode includes a positive electrode active material that comprises a lithium-containing manganese oxide, and the negative electrode includes a negative electrode active material that comprises silicon and a transition metal element. When the battery voltage is 0 V, the positive electrode and the negative electrode have a potential of 1.8 V or higher relative to lithium metal (Li/Li+). Since the deterioration of the positive and negative electrode active materials is suppressed, this non-aqueous electrolyte secondary battery has both high capacity and excellent deep discharge cycle life.
    Type: Application
    Filed: August 14, 2006
    Publication date: March 1, 2007
    Inventors: Teruaki Yamamoto, Tomohiro Ueda, Shinichi Waki, Youko Sano, Yasuhiko Bito
  • Publication number: 20070048596
    Abstract: A lithium ion secondary battery that offers high thermal stability. The lithium ion secondary battery includes a positive electrode capable of absorbing and desorbing lithium ions, a negative electrode capable of absorbing and desorbing lithium ions, and a non-aqueous electrolyte, wherein a difference ?T between a temperature T1 and a temperature T2 is equal to 50° C. or greater, where the T1 is a temperature at which the heat generation rate of the positive electrode in a charged state reaches the maximum, and the T2 is a temperature at which the heat generation rate of the negative electrode in a charged state reaches the maximum.
    Type: Application
    Filed: August 14, 2006
    Publication date: March 1, 2007
    Inventors: Masaki Hasegawa, Yasuhiko Bito
  • Publication number: 20070003835
    Abstract: A composite particle for a lithium rechargeable battery is contained in at least one of a positive electrode and a negative electrode of the lithium rechargeable battery that includes the positive electrode, the negative electrode, a separator, and non-aqueous electrolytic solution. The composite particle contains a conductive agent and an active material that can reversibly store and emit lithium ions. The composite particle is a hollow body formed of an outer wall including the active material and conductive agent, and a cavity capable of retaining non-aqueous electrolytic solution. At least one opening of the cavity that can pass the electrolytic solution is formed in the surface of the composite particle.
    Type: Application
    Filed: May 26, 2006
    Publication date: January 4, 2007
    Inventors: Masaki Hasegawa, Yasuhiko Bito
  • Publication number: 20060286458
    Abstract: A non-aqueous electrolyte secondary battery including: a positive electrode; a negative electrode, and a non-aqueous electrolyte. The negative electrode includes a negative electrode active material that includes at least Si. The non-aqueous electrolyte includes lithium hexafluorophosphate as a main supporting electrolyte and has an acid content of not less than 50 ppm and not more than 200 ppm. The negative electrode has a potential of not less than 0.6 V and not more than 1.5 V relative to a Li electrode at an end-of-discharge voltage of the battery. The battery is prevented from suffering degradation of storage characteristics caused by the dissolution reaction of Si from the negative electrode during charging and the precipitation reaction of the dissolved Si.
    Type: Application
    Filed: June 13, 2006
    Publication date: December 21, 2006
    Inventors: Toshitada Sato, Yasuhiko Bito, Masaya Ugaji
  • Publication number: 20060147800
    Abstract: A nonaqueous electrolyte secondary battery with excellent charging/discharging cycle characteristics is provided, more specifically a nonaqueous electrolyte secondary battery in which deterioration of the conductivity of a negative electrode due to charging/discharging cycle is suppressed and a method for manufacturing the same are provided. The nonaqueous electrolyte secondary battery includes: a positive electrode and a negative electrode that are capable of reversibly absorbing and desorbing Li ions; and a nonaqueous electrolyte having lithium ion conductivity. The negative electrode includes a collector and active material particles that are disposed on a surface of the collector. The active material particles include Si and at least one element R selected from the group consisting of Sn, In, Ga, Pb and Bi. Metallic bond including the element R is formed between the active material particles.
    Type: Application
    Filed: May 21, 2004
    Publication date: July 6, 2006
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Toshitada Sato, Harunari Shimamura, Hideaki Ohyama, Yasuhiko Bito
  • Publication number: 20060105242
    Abstract: A negative electrode containing an alloying material and a graphite material for providing a non-aqueous electrolyte secondary battery with a high capacity and excellent cycle characteristics. The negative electrode includes graphite and an alloying material capable of electrochemically absorbing and desorbing Li. The alloying material includes an A phase composed mainly of Si and a B phase including an intermetallic compound of a transition metal element and Si. The A phase and/or the B phase include a microcrystalline or amorphous region. The weight percentage of the A phase relative to the total weight of the A phase and the B phase is greater than 40% and not greater than 95%. The weight percentage of the graphite relative to the total weight of the alloying material and the graphite is not less than 50% and not greater than 95%.
    Type: Application
    Filed: May 2, 2005
    Publication date: May 18, 2006
    Inventors: Toshitada Sato, Masaki Hasegawa, Teruaki Yamamoto, Yasuhiko Bito
  • Publication number: 20060102472
    Abstract: A non-aqueous electrolyte secondary battery that has a high electrical capacity and exhibits excellent cycle characteristics even when the battery is rapidly charged and discharged at a large current includes: a positive electrode capable of reversibly absorbing and desorbing Li; a negative electrode; and a non-aqueous electrolyte. The negative electrode includes an alloying material that is capable of electrochemically absorbing and desorbing Li, and includes an A phase composed mainly of Si and a B phase including an intermetallic compound of at least one transition metal element and Si. The transition metal element is selected from the group consisting of Ti, Zr, Ni, Cu, and Fe. The A phase and/or the B phase includes a microcrystalline or amorphous region. The weight percent of the A phase relative to the total weight of the A phase and the B phase is greater than 40% and not greater than 95%.
    Type: Application
    Filed: July 6, 2005
    Publication date: May 18, 2006
    Inventors: Yasuhiko Bito, Toshitada Sato, Teruaki Yamamoto
  • Publication number: 20060102474
    Abstract: A negative electrode containing an alloying material and a graphite material for providing a non-aqueous electrolyte secondary battery with a high capacity and excellent cycle characteristics. The negative electrode includes graphite and at least one alloying material capable of electrochemically absorbing and desorbing Li. The alloying material includes an A phase composed mainly of Si and a B phase including an intermetallic compound of at least one transition metal element and Si. At least one of the A phase and the B phase includes a microcrystalline or amorphous region. The weight percentage of the A phase relative to the total weight of the A phase and the B phase is greater than 40% and not greater than 95%. The weight percentage of the graphite relative to the total weight of the alloying material and the graphite is not less than 50% and not greater than 95%.
    Type: Application
    Filed: October 26, 2005
    Publication date: May 18, 2006
    Inventors: Toshitada Sato, Masaki Hasegawa, Teruaki Yamamoto, Yasuhiko Bito
  • Publication number: 20060102473
    Abstract: A non-aqueous electrolyte secondary battery that has a high electrical capacity and exhibits excellent cycle characteristics even when the battery is rapidly charged and discharged at a large current includes: a positive electrode capable of reversibly absorbing and desorbing Li; a negative electrode; and a non-aqueous electrolyte. The negative electrode includes an alloying material that is capable of electrochemically absorbing and desorbing Li, and includes an A phase composed mainly of Si and a B phase including an intermetallic compound of at least one transition metal element and Si. The transition metal element is selected from the group consisting of Ti, Zr, Ni, Cu, and Fe. At least one of the A phase and the B phase includes a microcrystalline or amorphous region. The weight percent of the A phase relative to the total weight of the A phase and the B phase is greater than 40% and not greater than 95%.
    Type: Application
    Filed: November 9, 2005
    Publication date: May 18, 2006
    Inventors: Yasuhiko Bito, Toshitada Sato, Teruaki Yamamoto, Tomohiro Ueda
  • Publication number: 20050287439
    Abstract: The present invention relates to a negative electrode material for non-aqueous electrolyte secondary batteries, characterized in that the negative electrode material comprises a composite particle including solid phases A and B, the solid phase A being dispersed in the solid phase B, and the ratio (IA/IB) of the maximum diffracted X-ray intensity (IA) attributed to the solid phase A to the maximum diffracted X-ray intensity (IB) attributed to the solid phase B satisfies 0.001?IA/IB?0.1, in terms of a diffraction line obtained by a wide-angle X-ray diffraction measurement of the composite particle. This negative electrode material is capable of suppressing of pulverization thereof due to repeated cycles. Further, the use of this negative electrode material allows production of a non-aqueous electrolyte secondary battery having a high capacity and an excellent cycle life characteristic.
    Type: Application
    Filed: March 17, 2003
    Publication date: December 29, 2005
    Inventors: Harunari Shimamura, Toshitada Sato, Takayuki Nakamoto, Yasuhiko Bito, Yoshiaki Nitta
  • Publication number: 20050237029
    Abstract: A charger for a secondary battery including a positive electrode, a negative electrode including lithium-containing silicon represented by the composition formula LixSi, and an electrolyte. This charger includes: (1) a voltage detector that detects voltage of the secondary battery that is being charged; and (2) a charge controller that calculates the value x in LixSi included in the secondary battery from an output of the voltage detector and stops the charging of the secondary battery when the calculated value x reaches a predetermined threshold value. The charge controller has at least one settable threshold value including a first threshold value, and the first threshold value is 2.33 or less. The use of this charger makes it possible to charge the secondary battery such that it has a high capacity, or a higher capacity if necessary, without accelerating the deterioration of cycle life.
    Type: Application
    Filed: April 19, 2005
    Publication date: October 27, 2005
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO.,LTD.
    Inventors: Hideharu Takezawa, Masaaki Kuranuki, Yasuhiko Bito
  • Publication number: 20050118502
    Abstract: A negative active material thin film containing silicon as a main component is formed on a collector. A composition gradient layer, in which a composition distribution of a main component element of the collector and silicon is varied smoothly, is formed in the vicinity of the interface between the collector and the negative active material thin film. The composition gradient layer contains at least one kind of third element selected from W, Mo, Cr, Co, Fe, Mn, Ni, and P, in addition to the elements contained in the collector and the elements contained in the negative active material thin film. The third element irregularizes the atomic arrangement at the interface between the collector and the negative active material thin film.
    Type: Application
    Filed: November 1, 2004
    Publication date: June 2, 2005
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuyoshi Honda, Kiichiro Oishi, Yasuhiko Bito, Takayuki Nakamoto
  • Publication number: 20050118503
    Abstract: A negative active material thin film provided on a collector layer directly or via an underlying layer has a multi-layered configuration including at least two silicon thin films containing silicon as a main component. Because of this, even when the thickness of the negative active material thin film is increased, the increase in thickness of one silicon thin film can be prevented by increasing the number of silicon thin films. Thus, the diameter of silicon particles substantially in an inverse truncated cone shape is not enlarged in the silicon thin film. Accordingly, in an energy device having a thin film mainly containing silicon as a negative active material, even when the thickness of the negative active material layer is increased to obtain a larger capacity, cycle characteristics are not degraded.
    Type: Application
    Filed: November 4, 2004
    Publication date: June 2, 2005
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuyoshi Honda, Kiichiro Oishi, Yasuhiko Bito, Takayuki Nakamoto
  • Publication number: 20050118504
    Abstract: An auxiliary film-forming source containing a main component element of a collector and a negative active material film-forming source for forming a negative active material thin film are placed adjacent to each other so that parts of film-forming particles from the respective sources are mixed with each other. The collector is moved relatively from the auxiliary film-forming source side to the negative active material film-forming source side, whereby a negative active material thin film containing silicon as a main component is formed on the collector by a vacuum film-forming process. A composition gradient layer, in which a composition distribution of a main component element of the collector and silicon constituting the negative active material is varied smoothly, is formed at the interface between the negative active material thin film and the collector.
    Type: Application
    Filed: November 10, 2004
    Publication date: June 2, 2005
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuyoshi Honda, Kiichiro Oishi, Yasuhiko Bito, Takayuki Nakamoto
  • Patent number: 6882130
    Abstract: The present invention provides a battery-driven electronic device for which a long time use of the battery can be achieved and mobile communications equipment such as a portable telephone. Even if the time at which the output voltage of a battery 201 becomes below the supply voltage required by a load 206 including a power amplifier for wireless communications comes earlier than a conventional lithium ion battery because of its discharge characteristics that the battery voltage change ratio is 0.25 or more, a step-up and -down converter 200 operates as follows. When the output voltage of the battery is higher than the supply voltage required by the load, the voltage is set to a predetermined supply voltage by the step-down operation mode. When the output voltage of the battery is decreased and becomes lower than the supply voltage required by the load, the voltage is set to a predetermined supply voltage by the step-up operation mode.
    Type: Grant
    Filed: April 17, 2002
    Date of Patent: April 19, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroyuki Handa, Takuya Ishii, Yasufumi Nakajima, Yasuhiko Bito, Shinji Kasamatsu, Yoshiaki Nitta
  • Publication number: 20050064291
    Abstract: A negative electrode for a non-aqueous electrolyte secondary battery including a current collector, and an electrode material layer including an electrode material capable of reversibly absorbing and desorbing Li ions is provided. The electrode material includes at least one element selected from the group consisting of Si, Sn and Al; the surface of the current collector is provided with protrusions; the electrode material layer is disposed on the surfaces of the current collector and the protrusions; and the protrusion has a portion facing the surface of the current collector other than a portion that is brought into contact with the current collector. Thus, a negative electrode for a non-aqueous electrolyte battery having high properties such as an energy density, charging/discharging cycle property, and the like, and a non-aqueous electrolyte secondary battery can be provided.
    Type: Application
    Filed: September 2, 2004
    Publication date: March 24, 2005
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Toshitada Sato, Miyuki Nakai, Emiko Igaki, Yasuhiko Bito
  • Publication number: 20040241548
    Abstract: The present invention provides a negative electrode active material for a non-aqueous electrolyte rechargeable battery capable of absorbing/desorbing lithium having: an inner layer including at least a material selected from the group consisting of Si, Sn, an alloy containing Si and an alloy containing Sn; and a surface layer including silicon oxide or tin oxide of 0.2 to 1,000 nm in average thickness formed on the inner layer. Use of the negative electrode active material allows obtaining a non-aqueous electrolyte rechargeable battery having high capacity, and excellent cycle life characteristic and high-temperature storage characteristic.
    Type: Application
    Filed: April 2, 2004
    Publication date: December 2, 2004
    Inventors: Takayuki Nakamoto, Yasuhiko Bito
  • Patent number: 6761998
    Abstract: A non-aqueous electrolyte secondary battery containing an alloy particle capable of absorbing and desorbing lithium in the negative electrode has a short cycle life and is insufficient in high-rate discharge characteristics, since the alloy particle is pulverized during charge/discharge cycles. In order to solve this problem, a negative electrode is employed, which comprises an alloy particle containing: at least two selected from the group consisting of metal elements and semimetal elements; oxygen; and nitrogen. It is preferred that the alloy particle have a phase A capable of electrochemically absorbing and desorbing lithium ion and a phase B having lithium ion conductivity or lithium ion permeability and that the phase B contain larger amounts of oxygen and nitrogen than the phase A.
    Type: Grant
    Filed: March 18, 2002
    Date of Patent: July 13, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toshitada Sato, Yasuhiko Bito, Kazuhiro Okamura, Yoshiaki Nitta
  • Patent number: 6733927
    Abstract: In a non-aqueous electrolyte secondary battery, the reaction between the non-aqueous electrolyte and the electrode is suppressed to reduce a decrease in the discharge capacity with the charge/discharge cycle progress and the deterioration of battery characteristics during high-temperature storage. At least one of a chargeable and dischargeable positive electrode, a non-aqueous electrolyte containing a lithium salt, and a chargeable and dischargeable negative electrode in a non-aqueous electrolyte secondary battery contains at least one selected from the group consisting of a phosphate having three aliphatic hydrocarbon groups having 7 to 12 carbon atoms, a phosphate having two aliphatic hydrocarbon groups having 1 to 12 carbon atoms or an aromatic hydrocarbon group, and a phosphate having an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group.
    Type: Grant
    Filed: March 23, 2001
    Date of Patent: May 11, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideharu Takezawa, Yasuhiko Bito, Hiromu Matsuda, Yoshinori Toyoguchi
  • Publication number: 20040067740
    Abstract: The present invention provides a battery-driven electronic device for which a long time use of the battery can be achieved and mobile communications equipment such as a portable telephone. Even if the time at which the output voltage of a battery 201 becomes below the supply voltage required by a load 206 including a power amplifier for wireless communications comes earlier than a conventional lithium ion battery because of its discharge characteristics that the battery voltage change ratio is 0.25 or more, a step-up and -down converter 200 operates as follows. When the output voltage of the battery is higher than the supply voltage required by the load, the voltage is set to a predetermined supply voltage by the step-down operation mode. When the output voltage of the battery is decreased and becomes lower than the supply voltage required by the load, the voltage is set to a predetermined supply voltage by the step-up operation mode.
    Type: Application
    Filed: June 20, 2003
    Publication date: April 8, 2004
    Inventors: Hiroyuki Handa, Takuya Ishii, Yasufumi Nakajima, Yasuhiko Bito, Shinji Kasamatsu, Yoshiaki Nitta