Patents by Inventor Yoshiaki Kumashiro

Yoshiaki Kumashiro 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: 9214701
    Abstract: Provided is a technique of achieving a longer-life lithium ion secondary battery. The lithium ion secondary battery includes a cathode including a cathode active material containing Mn, an anode including an anode active material containing graphite and non-aqueous electrolytic solution including electrolyte, and LiBF4 and LiPF6 are allowed to coexist in the non-aqueous electrolytic solution. Especially preferably LiPF6 is contained more than LiBF4 in the electrolytic solution. Preferably the electrolytic solution further includes iodide salt. As a result, an oxide of phosphor and boron is deposited on the cathode, thus preventing elution of Mn included in the cathode. The amount of these electrolytes is preferably in the decreasing order of phosphor, boron and then iodine.
    Type: Grant
    Filed: August 19, 2011
    Date of Patent: December 15, 2015
    Assignee: Shin-Kobe Electric Machinery Co., Ltd.
    Inventors: Katsunori Nishimura, Yoshiaki Kumashiro, Kazushige Kohno, Toshiyuki Kobayashi
  • Publication number: 20130202957
    Abstract: Provided is a technique of achieving a longer-life lithium ion secondary battery. The lithium ion secondary battery includes a cathode including a cathode active material containing Mn, an anode including an anode active material containing graphite and non-aqueous electrolytic solution including electrolyte, and LiBF4 and LiPF6 are allowed to coexist in the non-aqueous electrolytic solution. Especially preferably LiPF6 is contained more than LiBF4 in the electrolytic solution. Preferably the electrolytic solution further includes iodide salt. As a result, an oxide of phosphor and boron is deposited on the cathode, thus preventing elution of Mn included in the cathode. The amount of these electrolytes is preferably in the decreasing order of phosphor, boron and then iodine.
    Type: Application
    Filed: August 19, 2011
    Publication date: August 8, 2013
    Applicant: Shin-Kobe Electrdic Machinery Co., Ltd.
    Inventors: Katsunori Nishimura, Yoshiaki Kumashiro, Kazushige Kohno, Toshiyuki Kobayashi
  • Publication number: 20130189591
    Abstract: The present invention aims to improve the fire resistance of an electrolytic solution used for a lithium-ion battery and improve the life characteristics of the lithium-ion battery. In the lithium ion battery of the present invention, specific amounts of ethylene carbonate and dimethyl carbonate are used for a non-aqueous electrolytic solution, and trimethyl phosphate is added thereto. Specifically, the non-aqueous electrolytic solution contains 60 vol % or more of ethylene carbonate (EC) and dimethyl carbonate (DMC). The volume ratio of DMC to the sum of EC and DMC is 0.3 to 0.6, and the non-aqueous electrolytic solution contains 3 to 5 wt % of trimethyl phosphate (TMP) with respect to the total weight of the non-aqueous electrolytic solution. Such a non-aqueous electrolytic solution has an effect of improving the self-fire extinguishing property, and thus improves the safety of the lithium-ion battery.
    Type: Application
    Filed: August 19, 2011
    Publication date: July 25, 2013
    Applicant: Shin-Kobe Ekectric Machinery Co., Ltd.
    Inventors: Katsunori Nishimura, Yoshiaki Kumashiro, Kazushige Kohno, Toshiyuki Kobayashi
  • Patent number: 8421418
    Abstract: In a charging/discharging unit provided with: a lithium secondary battery, a voltage detecting sensor for detecting a voltage and a current detecting sensor; the charging/discharging control unit is further provided with a controller, and a discharging element for performing a constant voltage discharging operation of 3 V. A voltage, V0, of the battery when a discharging operation is terminated (t=0) is measured by the voltage detecting sensor. If V0?3.6 V, within a rest time during which the battery is not charged/discharged until a next charging operation, a voltage, V1, of the battery when a time, t1, has elapsed is measured by the voltage detecting sensor. If this voltage charge is in a range of V1-V0?0.2 V, then the constant voltage discharging operation of 3 V is carried out for a time duration longer than or equal to 1 hour.
    Type: Grant
    Filed: August 14, 2009
    Date of Patent: April 16, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Yoshiaki Kumashiro, Yoshimi Yanai, Eiji Seki
  • Patent number: 8338033
    Abstract: A nonaqueous lithium secondary battery includes a positive electrode and a negative electrode capable of intercalating and releasing lithium ions and a separator. The negative electrode includes a collector and a negative electrode mixture layer formed on the collector. The negative electrode mixture layer includes at least a negative electrode active material and a binder. Nonconductive particles are buried in a top layer of the negative electrode mixture layer. The nonconductive particles and the negative electrode active material exist as a mixture in the top layer with a depth ranging from 1 to 20 ?m. A volume ratio of nonconductive particles having a diameter equal to or less than 20 ?m to a total volume of all the nonconductive particles and the negative electrode active material existing in the top layer of the negative electrode mixture layer ranges from 20 to 80%.
    Type: Grant
    Filed: August 5, 2010
    Date of Patent: December 25, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Masao Shimizu, Yoshiaki Kumashiro
  • Publication number: 20120226455
    Abstract: A lithium secondary cell has a positive electrode, a negative electrode, and an electrolyte including lithium ions. An anomalously charged state detection device includes: a voltage detection unit; a current detection unit; a calculation unit that calculates the electricity amount Q charged into or discharged from the lithium secondary cell and a differential value dV/dQ for each predetermined time period t, and that obtains a Q-dV/dQ curve; a measured data storage unit that stores the Q-dV/dQ curve; a cell data storage unit that stores a Q-dV/dQ curve during normal conditions; and a control unit that decides that the lithium secondary cell is in an anomalously charged state if, in the Q-dV/dQ curve stored by the measured data storage unit, a peak is present that is different from a peak that appears in the Q-dV/dQ curve during normal conditions.
    Type: Application
    Filed: February 29, 2012
    Publication date: September 6, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Yoshiaki KUMASHIRO, Tsunenori Yamamoto, Osamu Kubota
  • Patent number: 8192871
    Abstract: To provide a lithium secondary battery which suppresses a decrease in the charge and discharge efficiency during a battery storage test and which is excellent in maintaining the battery capacity after the storage test.
    Type: Grant
    Filed: February 19, 2009
    Date of Patent: June 5, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Haruna, Kazushige Kohno, Eiji Seki, Yoshiaki Kumashiro
  • Publication number: 20110033754
    Abstract: A nonaqueous lithium secondary battery includes a positive electrode and a negative electrode capable of intercalating and releasing lithium ions and a separator. The negative electrode includes a collector and a negative electrode mixture layer formed on the collector. The negative electrode mixture layer includes at least a negative electrode active material and a binder. Nonconductive particles are buried in a top layer of the negative electrode mixture layer. The nonconductive particles and the negative electrode active material exist as a mixture in the top layer with a depth ranging from 1 to 20 ?m. A volume ratio of nonconductive particles having a diameter equal to or less than 20 ?m to a total volume of all the nonconductive particles and the negative electrode active material existing in the top layer of the negative electrode mixture layer ranges from 20 to 80%.
    Type: Application
    Filed: August 5, 2010
    Publication date: February 10, 2011
    Inventors: Masao SHIMIZU, Yoshiaki Kumashiro
  • Publication number: 20100072949
    Abstract: In a charging/discharging unit provided with: a lithium secondary battery, a voltage detecting sensor for detecting a voltage and a current detecting sensor; the charging/discharging control unit is further provided with a controller, and a discharging element for performing a constant voltage discharging operation of 3 V. A voltage, V0, of the battery when a discharging operation is terminated (t=0) is measured by the voltage detecting sensor. If V0?3.6 V, within a rest time during which the battery is not charged/discharged until a next charging operation, a voltage, V1, of the battery when a time, t1, has elapsed is measured by the voltage detecting sensor. If this voltage charge is in a range of V1?V0?0.2 V, then the constant voltage discharging operation of 3 V is carried out for a time duration longer than or equal to 1 hour.
    Type: Application
    Filed: August 14, 2009
    Publication date: March 25, 2010
    Applicant: Hitachi, Ltd.
    Inventors: Yoshiaki Kumashiro, Yoshimi Yanai, Eiji Seki
  • Publication number: 20090263721
    Abstract: To provide a lithium secondary battery which suppresses a decrease in the charge and discharge efficiency during a battery storage test and which is excellent in maintaining the battery capacity after the storage test.
    Type: Application
    Filed: February 19, 2009
    Publication date: October 22, 2009
    Inventors: Hiroshi Haruna, Kazushige Kohno, Eiji Seki, Yoshiaki Kumashiro
  • Publication number: 20070003838
    Abstract: An energy device with high input/output characteristics and superior characteristics particularly at low temperature. The energy device stores and releases electric energy by means of a faradaic reaction mechanism based mainly on the alteration of the oxidation state of an active material whereby charges move into the active material, and a non-faradaic reaction based mainly on the physical adsorption and separation of ions on the surface of an active material for storing or releasing charges. The output characteristics at low temperature are improved by employing at least two kinds of faradaic reaction mechanism, namely, one with low reaction rate and the other with high reaction rate, which is mainly based on the alteration of the oxide state of an active material for the transfer of charges into the active material via an electrode interface.
    Type: Application
    Filed: August 18, 2005
    Publication date: January 4, 2007
    Inventors: Yoshiaki Kumashiro, Juichi Arai, Mituru Kobayashi
  • Publication number: 20060269802
    Abstract: A long-life electric energy storage device with superior high-input/output load resistance includes a cathode including a region having a faradic reaction mechanism and a region having a non-faradic reaction mechanism, and an anode including a region having a faradic reaction mechanism. When carbon material contained in the anode is represented by a diffraction line according to X-ray diffraction method, mainly the (001) plane is substantially detected.
    Type: Application
    Filed: May 23, 2006
    Publication date: November 30, 2006
    Inventors: Takahiro Yamaki, Juichi Arai, Yoshiaki Kumashiro
  • Publication number: 20060134515
    Abstract: An object of the present invention is to provide an energy device excellent in input/output characteristics at a low temperature and various applications using the same. The present invention consists in an energy device comprising a positive electrode having a region where a faradic reaction occurs, and a negative electrode having a region where a faradic reaction occurs, wherein at least one of the positive and negative electrodes has a region where a faradic reaction having a reaction rate higher than that of the faradic reaction occurs or a region where a non-faradic reaction occurs.
    Type: Application
    Filed: December 15, 2005
    Publication date: June 22, 2006
    Inventors: Yoshiaki Kumashiro, Juichi Arai, Mituru Kobayashi, Masanori Yoshikawa, Takahiro Yamaki
  • Publication number: 20060124973
    Abstract: An object of the present invention is to provide an energy storage device excellent in input/output characteristics at low temperatures, a module thereof and a vehicle using the module. The present invention provides an energy storage device comprising: a positive electrode having a region where a reaction accompanied by charge exchange occurs; a negative electrode having a region where a reaction accompanied by charge exchange occurs; a separator electrically separating the positive and negative electrodes and allowing mobile ions to pass therethrough; an electrolytic solution having an aprotic nonaqueous solvent comprising the mobile ions; and a region in at least one of the positive and negative electrodes where a charge adsorbing/desorbing reaction occurs.
    Type: Application
    Filed: December 13, 2005
    Publication date: June 15, 2006
    Inventors: Juichi Arai, Yoshiaki Kumashiro, Masanori Yoshikawa, Mituru Kobayashi, Takahiro Yamaki
  • Publication number: 20060127771
    Abstract: An energy storage device of excellent input/output characteristics and having high density of stored energy, the device having a cathode comprising a material conducting faradic reaction and a material conducting non-faradic reaction, and an anode comprising a material conducting faradic reaction, in which the faradic reaction is desorption/intercalation reaction of lithium ions, higher input/output characteristics being obtainable by providing a mix layer comprising a material conducting faradic reaction on a cathode collector and providing a material layer conducting non-faradic reaction further to the surface layer thereof.
    Type: Application
    Filed: August 18, 2005
    Publication date: June 15, 2006
    Inventors: Takahiro Yamaki, Juichi Arai, Yoshiaki Kumashiro
  • Publication number: 20050260497
    Abstract: An energy storage device comprising a negative electrode plate having a negative electrode active material layer of a carbonaceous composite material formed on a negative electrode collector, a positive electrode plate having a positive electrode active material layer capable of inserting and releasing lithium ions and a non-faradic reaction layer capable of accumulating and releasing electric charges upon physical adsorption-desorption of ions on the surface layer of the positive electrode active material layer and an insulator layer for electrically insulating the positive electrode plate from the negative electrode plate, the insulator layer being capable of permeating only mobile ions. The carbonaceous composite material comprises particles of graphite and/or amorphous carbon and activated charcoal, and the particles of the graphite and/or amorphous carbon and particles of the activated charcoal are united.
    Type: Application
    Filed: February 17, 2005
    Publication date: November 24, 2005
    Inventors: Yoshiaki Kumashiro, Juichi Arai, Mituru Kobayasi
  • Publication number: 20050250014
    Abstract: An energy storage device comprising a positive active material layer having a positive active material capable of inserting and releasing lithium ions, a positive electrode plate having a layer capable of effecting non-faradic like reaction upon physical adsorption and desorption of the ions to accumulate and discharge charges, and a negative plate having a negative active material layer made of carbonaceous material that is capable of absorbing and releasing mainly lithium in the ionized state in a collector, and an insulator layer for electrically insulating the positive electrode plate from the negative electrode plate that causes only mobile ions permeate.
    Type: Application
    Filed: February 18, 2005
    Publication date: November 10, 2005
    Inventors: Yoshiaki Kumashiro, Juichi Arai, Mituru Kobayasi
  • Publication number: 20050153173
    Abstract: An energy device having high input-output performance, in particular being excellent in low temperature performance. An energy device characterized by storing and discharging electric energy by both a faradaic reaction mechanism wherein mainly the oxidation state of an active material changes and electric charge transfers inside said active material and a non-faradaic reaction mechanism wherein mainly ions are physically absorbed and desorbed on the surface of an active material and resultantly electric charge is accumulated and discharged. Further, output performance at a low temperature is improved by providing an energy device characterized by storing and discharging electric energy by at least two kinds of reaction mechanisms that show low and high reaction rates respectively in faradaic reaction wherein mainly the oxidation state of an active material changes and electric charge transfers to said active material through an electrode interface.
    Type: Application
    Filed: January 10, 2005
    Publication date: July 14, 2005
    Inventors: Yoshiaki Kumashiro, Juichi Arai, Mituru Kobayashi, Eiji Hoshi
  • Publication number: 20050089728
    Abstract: To acquire a high-output electrochemical energy storage device the range of operating voltage of which is large, a positive electrode provided with a positive electrode collector and positive electrode active material which is held by the positive electrode collector and can occlude/emit a metal ion, a negative electrode provided with a negative electrode collector and negative electrode active material which is held by the negative electrode collector and can occlude/emit the metal ion, a minutely porous separator held between the positive electrode and the negative electrode and an organic electrolyte are provided, and a range of operating voltage is equivalent to a range from below 2 V to 4 V or more.
    Type: Application
    Filed: February 26, 2004
    Publication date: April 28, 2005
    Inventors: Juichi Arai, Yoshiaki Kumashiro, Mituru Kobayasi
  • Publication number: 20040202933
    Abstract: A lithium ion secondary battery having high energy density and of excellent safety, and a cathode active material used therefor are provided. The cathode active material is a Li-containing composite oxide comprising a plurality of transition metal elements selected from Cr, Mn, Fe, Co, Ni and Cu, in which the composition of the transition metal elements is in a range not inclined to particular transition metal elements. The composite oxide having a crystal structure in which the range of an angle &bgr; formed between a axis and b axis of the crystallographic structure is controlled as: 90° <&bgr;≦110°. The composite oxide is used as the cathode active material of a lithium ion secondary battery.
    Type: Application
    Filed: July 16, 2002
    Publication date: October 14, 2004
    Inventors: Takahiro Yamaki, Masahiro Kasai, Yoshiaki Kumashiro, Takayuki Hirashige