Patents by Inventor Jiro Iriyama

Jiro Iriyama 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: 9263741
    Abstract: There is provided a negative electrode for a nonaqueous electrolyte secondary battery in which when a battery is formed, the energy density is high, and moreover, the decrease in charge and discharge capacity is small even if charge and discharge are repeated. By using silicon oxide particles having a particle diameter in a particular range as a starting raw material, and heating these particles in the range of 850° C. to 1050° C., Si microcrystals are deposited on the surfaces of the particles. Then, by performing doping of Li, a structure comprising a plurality of protrusions having height and cross-sectional area in a particular range is formed on the surfaces. The average value of the height of the above protrusions is 2% to 19% of the average particle diameter of the above lithium-containing silicon oxide particles.
    Type: Grant
    Filed: December 17, 2009
    Date of Patent: February 16, 2016
    Assignee: NEC Energy Devices, Ltd.
    Inventors: Jiro Iriyama, Ryuichi Kasahara, Tetsuya Kajita, Tatsuji Numata
  • Publication number: 20160036051
    Abstract: The present invention relates to a lithium secondary battery, wherein a peak at 167 to 171 eV and a peak at 162 to 166 eV are present in XPS analysis of sulfur (S2p) of a positive electrode surface, and P169/P164 is in the range of 0.7 to 2.0 wherein the P 169/P 164 is the ratio between the intensity of the peak at 167 to 171 eV (P169) and the intensity of the peak at 162 to 166 eV (P164). The present invention can provide a lithium secondary battery having excellent cycle characteristics.
    Type: Application
    Filed: March 4, 2014
    Publication date: February 4, 2016
    Applicant: NEC Corporation
    Inventor: Jiro IRIYAMA
  • Patent number: 9203107
    Abstract: An exemplary embodiment provides a lithium ion secondary battery using a high energy type anode, which enables long-life operation thereof. A secondary battery according to an exemplary embodiment comprises an electrode element in which a cathode and an anode are oppositely disposed, an electrolytic solution, and an outer packaging body which encloses the electrode element and the electrolytic solution inside; wherein the anode is formed by binding an anode active material, which comprises carbon material (a) that can absorb and desorb a lithium ion, metal (b) that can be alloyed with lithium, and metal oxide (c) that can absorb and desorb a lithium ion, to an anode collector with an anode binder; and wherein the electrolytic solution comprises a liquid medium which is hard to generate carbon dioxide at a concentration of 10 to 75 vol %.
    Type: Grant
    Filed: September 29, 2010
    Date of Patent: December 1, 2015
    Assignees: NEC ENERGY DEVICES, LTD., NEC CORPORATION
    Inventors: Daisuke Kawasaki, Shinako Kaneko, Jiro Iriyama
  • Publication number: 20150303518
    Abstract: The present invention provides a lithium secondary battery, wherein a peak at 167 to 171 eV and a peak at 160 to 164 eV are present in XPS analysis of sulfur on a negative electrode surface (S2p), and P169/P162 is in the range of 0.7 to 2.0 wherein the P169/P162 is the ratio between the intensity of the peak at 167 to 171 eV (P169) and the intensity of the peak at 160 to 164 eV (P162).
    Type: Application
    Filed: October 29, 2013
    Publication date: October 22, 2015
    Inventor: Jiro IRIYAMA
  • Patent number: 9160004
    Abstract: In a lithium ion secondary battery including a positive electrode, a separator, and a negative electrode opposed to the positive electrode with an intervention of the separator, the negative electrode includes a negative electrode active material including a silicon compound, and a negative electrode binder including a particular polyimide, and lithium is occluded in both the negative electrode active material and the negative electrode binder even during discharge.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: October 13, 2015
    Assignee: NEC Corporation
    Inventors: Ryuichi Kasahara, Jiro Iriyama, Kazuhiko Inoue
  • Patent number: 9123928
    Abstract: The object of an exemplary embodiment of the invention is to provide a negative electrode having excellent cycle property. An exemplary embodiment of the invention a method for doping and dedoping lithium for the first time after a negative electrode for a lithium secondary battery comprising silicon oxide as an active material is produced, comprising doping the lithium within the following current value range (A) and within the following doped amount range (B); current value range (A): a range of a current value in which a doped amount in which only one peak appears at 1 V or less on the V-dQ/dV curve becomes maximum, wherein the V-dQ/dV curve represents a relationship between voltage V of the negative electrode with respect to a lithium reference electrode and dQ/dV that is a ratio of variation dQ of lithium dedoped amount Q in the negative electrode to variation dV of the voltage V, and doped amount range (B): a range of a doped amount in which only one peak appears at 1 V or less on the V-dQ/dV curve.
    Type: Grant
    Filed: April 6, 2012
    Date of Patent: September 1, 2015
    Assignee: NEC Corporation
    Inventors: Jiro Iriyama, Tetsuya Kajita, Daisuke Kawasaki, Tatsuji Numata
  • Publication number: 20150200425
    Abstract: There is provided a control system for a lithium secondary battery that can quantitatively sense a deterioration state inherent in a lithium secondary battery using silicon oxide as a negative electrode active material, that is, the nonuniform reaction state of a negative electrode.
    Type: Application
    Filed: March 27, 2015
    Publication date: July 16, 2015
    Applicants: NEC ENERGY DEVICES, LTD., NEC CORPORATION
    Inventors: Jiro IRIYAMA, Tetsuya KAJITA, Daisuke KAWASAKI, Ryuichi KASAHARA, Tatsuji NUMATA
  • Patent number: 9076995
    Abstract: A secondary battery according to the present exemplary embodiment is a secondary battery including a laminated electrode body provided with at least one pair of positive and negative electrodes and an outer enclosure that accommodates the laminated electrode body, wherein the outer enclosure includes one or more concave portions, inside a border corresponding to an outer edge of an electrode surface of an outermost layer of the laminated electrode body, on a surface facing the electrode surface, and wherein, when a band-shaped outer circumferential region having an area that is a half of an area inside the border is set inside the border, at least one of the concave portions is located inside the outer circumferential region.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: July 7, 2015
    Assignee: NEC CORPORATION
    Inventors: Shin Serizawa, Hiroo Takahashi, Daisuke Kawasaki, Jiro Iriyama, Ryuichi Kasahara, Emiko Fujii, Tetsuya Kajita, Tatsuji Numata
  • Patent number: 9018916
    Abstract: There is provided a control system for a lithium secondary battery that can quantitatively sense a deterioration state inherent in a lithium secondary battery using silicon oxide as a negative electrode active material, that is, the nonuniform reaction state of a negative electrode.
    Type: Grant
    Filed: July 20, 2011
    Date of Patent: April 28, 2015
    Assignees: NEC Corporation, NEC Energy Devices, Ltd.
    Inventors: Jiro Iriyama, Tetsuya Kajita, Daisuke Kawasaki, Ryuichi Kasahara, Tatsuji Numata
  • Publication number: 20150072220
    Abstract: Provided are a lithium secondary battery wherein gas generation associated with charging and discharging can be suppressed even in case where silicon and silicon oxide are contained as negative electrode active materials, and wherein deformation due to the gas generation can be suppressed even in case where a resin film is used as an outer package; and a method for manufacturing the lithium secondary battery. A lithium secondary battery comprises a negative electrode containing a negative electrode active material, a positive electrode containing a positive electrode active material, and an electrolytic solution used to immerse the negative electrode active material and the positive electrode active material, wherein the negative electrode active material contains silicon and silicon oxide that have been subjected to a reduction treatment.
    Type: Application
    Filed: March 22, 2013
    Publication date: March 12, 2015
    Applicant: NEC CORPORATION
    Inventors: Tetsuya Kajita, Jiro Iriyama, Shin Serizawa
  • Patent number: 8956762
    Abstract: In a lithium ion secondary battery including a positive electrode, a separator, a negative electrode, and a package body, the negative electrode includes simple substance silicon as a negative electrode active material, and a negative electrode binder, and is doped with lithium, and the following formulas (1) and (2) are satisfied: 1.2?Ma/Mc?1.9??(1) 1.0<Ma/(Mc+MLi)<1.6??(2) wherein an amount of lithium inserted into the negative electrode until the negative electrode reaches a potential of 0.02 V with respect to metal lithium is Ma (a number of atoms), an amount of lithium released from the positive electrode until the positive electrode reaches a potential of 4.3 V with respect to metal lithium is Mc (a number of atoms), and an amount of lithium with which the negative electrode is doped is MLi (a number of atoms).
    Type: Grant
    Filed: July 29, 2011
    Date of Patent: February 17, 2015
    Assignees: NEC Corporation, NEC Energy Devices, Ltd.
    Inventors: Ryuichi Kasahara, Jiro Iriyama, Tetsuya Kajita, Hiroo Takahashi, Tatsuji Numata, Daisuke Kawasaki
  • Publication number: 20150037671
    Abstract: It is an object of the exemplary embodiment of the present invention to provide a method for manufacturing a negative electrode for a lithium secondary battery by which conductive metal particles can be uniformly and easily formed in a conductive intermediate layer. The exemplary embodiment of the present invention is a method for manufacturing a negative electrode for a lithium secondary battery comprising a current collector comprising a metal, an active material layer comprising an active material and a binding agent, and a conductive intermediate layer comprising conductive metal particles between the current collector and the active material layer, comprising steps of (1) placing a polyamic acid on the current collector; (2) causing the metal to move from the current collector into the polyamic acid by generating migration phenomenon; and (3) heating and curing the polyamic acid, in this order, wherein the metal that has moved into the polyamic acid forms the conductive metal particles.
    Type: Application
    Filed: October 16, 2012
    Publication date: February 5, 2015
    Inventors: Jiro Iriyama, Tetsuya Kajita
  • Publication number: 20140356711
    Abstract: In a lithium ion secondary battery including a positive electrode, a separator, and a negative electrode opposed to the positive electrode with an intervention of the separator, the negative electrode includes a negative electrode active material including a silicon compound, and a negative electrode binder including a particular polyimide, and lithium is occluded in both the negative electrode active material and the negative electrode binder even during discharge.
    Type: Application
    Filed: September 13, 2012
    Publication date: December 4, 2014
    Inventors: Ryuichi Kasahara, Jiro Iriyama, Kazuhiko Inoue
  • Patent number: 8728662
    Abstract: Disclosed is a polyradical compound which can be used as an electrode active material for at least one of a positive electrode and a negative electrode. The polyradical compound has a repeating unit represented by general formula (1) and is crosslinked using a bifunctional crosslinking agent having two polymerizing groups in the molecule represented by general formula (2), wherein R1 to R3 each independently represent hydrogen or methyl group; R4 to R7 each independently represent C1 to C3 alkyl group; X represents single bond, linear, branched or cyclic C1 to C15 alkylenedioxy group, alkylene group, phenylenedioxy group, phenylene group or structure represented by general formula (3); and R8 to R13 each independently represent hydrogen or methyl group, and k represents an integer of 2 to 5.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: May 20, 2014
    Assignee: NEC Corporation
    Inventors: Masahiro Suguro, Shigeyuki Iwasa, Yuki Kusachi, Jiro Iriyama, Yukiko Morioka, Kentaro Nakahara, Sadahiko Miura
  • Publication number: 20140127557
    Abstract: The object of an exemplary embodiment of the invention is to provide a lithium ion secondary battery having an excellent charge and discharge cycle property. An exemplary embodiment of the invention is a lithium ion secondary battery, comprising a battery assembly in which a positive electrode and a negative electrode are stacked through a separator and a package in which the battery assembly and an electrolyte are placed; wherein the negative electrode comprises a negative electrode collector which is composed of a metal and a negative electrode active material layer which is formed on the negative electrode collector and which comprises a negative electrode active material and a binder; wherein the negative electrode collector and the negative electrode active material layer have a crack which is formed so as to be communicated with each of them; and wherein the crack reaches an outer peripheral edge from an inside of the negative electrode.
    Type: Application
    Filed: April 13, 2012
    Publication date: May 8, 2014
    Inventors: Ryuichi Kasahara, Jiro Iriyama, Shin Serizawa, Hiroo Takahashi, Tatsuji Numata
  • Publication number: 20140076729
    Abstract: The object of an exemplary embodiment of the invention is to provide a negative electrode having excellent cycle property. An exemplary embodiment of the invention a method for doping and dedoping lithium for the first time after a negative electrode for a lithium secondary battery comprising silicon oxide as an active material is produced, comprising doping the lithium within the following current value range (A) and within the following doped amount range (B); current value range (A): a range of a current value in which a doped amount in which only one peak appears at 1 V or less on the V-dQ/dV curve becomes maximum, wherein the V-dQ/dV curve represents a relationship between voltage V of the negative electrode with respect to a lithium reference electrode and dQ/dV that is a ratio of variation dQ of lithium dedoped amount Q in the negative electrode to variation dV of the voltage V, and doped amount range (B): a range of a doped amount in which only one peak appears at 1 V or less on the V-dQ/dV curve.
    Type: Application
    Filed: April 6, 2012
    Publication date: March 20, 2014
    Inventors: Jiro Iriyama, Tetsuya Kajita, Daisuke Kawasaki, Tatsuji Numata
  • Publication number: 20140045063
    Abstract: Provided is a negative electrode active material for a lithium secondary cell, the material having the function of a binder for the active material, and being capable of stable reversible reactions with lithium. Also, provided are an extended-life lithium secondary cell having improved energy density and stable charge/discharge, and a method for producing the same. The negative electrode active material for a lithium secondary cell is polyimide represented by formula (1) (wherein R1 and R2 independently denote an alkyl, alkoxy, acyl, phenyl, or phenoxy group).
    Type: Application
    Filed: April 27, 2012
    Publication date: February 13, 2014
    Inventors: Jiro Iriyama, Tetsuya Kajita, Daisuke Kawasaki, Tatsuji Numata, Kazuhiko Inoue
  • Publication number: 20130280594
    Abstract: In a nonaqueous electrolyte secondary battery using silicon and silicon oxide as a negative electrode active material, the charge and discharge cycle characteristics are improved. A nonaqueous electrolyte secondary battery in the exemplary embodiment comprises a sheet-shaped negative electrode comprising a negative electrode active material layer comprising a composite of silicon and silicon oxide formed on a negative electrode current collector, and a sheet-shaped positive electrode comprising a positive electrode active material layer formed on a positive electrode current collector, wherein the negative electrode is disposed opposed to the positive electrode via a separator, a peripheral edge portion of the negative electrode active material layer is disposed within a peripheral edge portion of the positive electrode active material layer, and a relationship of 1.00<c is satisfied when a charge capacity of the positive electrode is a, a charge capacity of the negative electrode is b, and b/a=c is set.
    Type: Application
    Filed: January 18, 2011
    Publication date: October 24, 2013
    Applicant: NEC ENERGY DEVICES, LTD.
    Inventors: Tetsuya Kajita, Ryuichi Kasahara, Jiro Iriyama, Tatsuji Numata
  • Publication number: 20130244086
    Abstract: Provided are a negative electrode for a secondary battery realizing satisfactory cycle characteristics and a method for manufacturing the same, and a nonaqueous electrolyte secondary battery having satisfactory cycle characteristics. A negative electrode for a secondary battery formed by bonding a negative electrode active material to a negative electrode collector with a negative electrode binder, in which the negative electrode binder is a polyimide or a polyamide-imide, and the negative electrode collector is a Cu alloy containing at least one metal (a) selected from the group consisting of Sn, In, Mg and Ag and has a conductivity of 50 IACS % or more.
    Type: Application
    Filed: August 25, 2011
    Publication date: September 19, 2013
    Applicant: NEC ENERGY DEVICES, LTD.
    Inventors: Jiro Iriyama, Daisuke Kawasaki, Ryuichi Kasahara, Tetsuya Kajita, Tatsuji Numata
  • Publication number: 20130119940
    Abstract: There is provided a control system for a lithium secondary battery that can quantitatively sense a deterioration state inherent in a lithium secondary battery using silicon oxide as a negative electrode active material, that is, the nonuniform reaction state of a negative electrode.
    Type: Application
    Filed: July 20, 2011
    Publication date: May 16, 2013
    Applicants: NEC ENERGY DEVICES, LTD., NEC CORPORATION
    Inventors: Jiro Iriyama, Tetsuya Kajita, Daisuke Kawasaki, Ryuichi Kasahara, Tatsuji Numata