Patents by Inventor Mayumi Mikami

Mayumi Mikami 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: 10388961
    Abstract: Provided are a binder composition for a secondary battery electrode that enables favorable dispersion of a conductive material when used in production of a slurry composition for a secondary battery electrode, and a slurry composition for a secondary battery electrode in which a conductive material is favorably dispersed. The binder composition for a secondary battery electrode contains a solvent and a copolymer including an alkylene structural unit and a nitrile group-containing monomer unit. The copolymer has a Mooney viscosity (ML1+4, 100° C.) of 40 or less. The slurry composition for a secondary battery electrode contains an electrode active material, a conductive material, the aforementioned binder composition for a secondary battery electrode, and a polymer other than the aforementioned copolymer.
    Type: Grant
    Filed: July 12, 2016
    Date of Patent: August 20, 2019
    Assignee: ZEON CORPORATION
    Inventors: Mayumi Fukumine, Jun Mikami, Tomoya Murase
  • Patent number: 10170764
    Abstract: An object is to form a positive electrode active material having small and highly uniform particles by a simple process. A template is formed by forming holes in the template by a nanoimprinting method, and the template is filled with a gel-like LiFePO4 material, whereby small-sized LiFePO4 particles are formed and are used as the positive electrode active material of a secondary battery. The particle size can be reduced to less than 50 nm. Further, when the LiFePO4 particles are sintered, the template may be burned down. By making the particle size of the positive electrode active material smaller than the conventional one, a positive electrode that lithium is injected into and extracted from easily can be manufactured.
    Type: Grant
    Filed: June 28, 2011
    Date of Patent: January 1, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Koji Nara, Mayumi Mikami
  • Publication number: 20180145368
    Abstract: Positive electrode active material particles that inhibit a decrease in capacity due to charge and discharge cycles are provided. A high-capacity secondary battery, a secondary battery with excellent charge and discharge characteristics, or a highly-safe or highly-reliable secondary battery is provided. A novel material, active material particles, and a storage device are provided. The positive electrode active material particle includes a first region and a second region in contact with the outside of the first region. The first region contains lithium, oxygen, and an element M that is one or more elements selected from cobalt, manganese, and nickel. The second region contains the element M, oxygen, magnesium, and fluorine. The atomic ratio of lithium to the element M (Li/M) measured by X-ray photoelectron spectroscopy is 0.5 or more and 0.85 or less. The atomic ratio of magnesium to the element M (Mg/M) is 0.2 or more and 0.5 or less.
    Type: Application
    Filed: November 13, 2017
    Publication date: May 24, 2018
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Ayae TSURUTA, Masahiro TAKAHASHI
  • Publication number: 20180102536
    Abstract: Provided is a positive electrode active material which suppresses a reduction in capacity due to charge and discharge cycles when used in a lithium ion secondary battery. A covering layer is formed by segregation on a superficial portion of the positive electrode active material. The positive electrode active material includes a first region and a second region. The first region exists in an inner portion of the positive electrode active material. The second region exists in a superficial portion of the positive electrode active material and part of the inner portion thereof. The first region includes lithium, a transition metal, and oxygen. The second region includes magnesium, fluorine, and oxygen.
    Type: Application
    Filed: October 6, 2017
    Publication date: April 12, 2018
    Inventors: Takahiro KAWAKAMI, Teruaki OCHIAI, Yohei MOMMA, Ayae TSURUTA, Masahiro TAKAHASHI, Mayumi MIKAMI
  • Publication number: 20180076489
    Abstract: A novel electrode, a novel power storage device, an electrode with less deterioration, an electrode with a high capacity, a long-life power storage device, a power storage device with less deterioration, a power storage device with high energy density, or a highly reliable power storage device is provided. The electrode includes a graphene compound including a graphene layer and a substituted or unsubstituted chain group, and an active material. The graphene layer is bonded to the chain group through a substituent containing silicon. The graphene compound includes a region in contact with the active material in particle form. The active material includes an element A, which is one or more elements selected from elements belonging to Group 1 and elements belonging to Group 2, and an element M, which is one or more elements selected from manganese and nickel. The chain group includes one or more groups selected from a carbonyl group, an ester group, a carboxyl group, an ether group, and an epoxy group.
    Type: Application
    Filed: September 8, 2017
    Publication date: March 15, 2018
    Inventors: Mayumi Mikami, Yohei Momma, Minoru Takahashi, Hiroshi Kadoma, Teppei Oguni, Satoshi Seo
  • Publication number: 20180013130
    Abstract: A positive electrode active material which can improve cycle characteristics of a secondary battery is provided. Two kinds of regions are provided in a superficial portion of a positive electrode active material such as lithium cobaltate which has a layered rock-salt crystal structure. The inner region is a non-stoichiometric compound containing a transition metal such as titanium, and the outer region is a compound of representative elements such as magnesium oxide. The two kinds of regions each have a rock-salt crystal structure. The inner layered rock-salt crystal structure and the two kinds of regions in the superficial portion are topotaxy; thus, a change of the crystal structure of the positive electrode active material generated by charging and discharging can be effectively suppressed.
    Type: Application
    Filed: June 30, 2017
    Publication date: January 11, 2018
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Patent number: 9774034
    Abstract: To increase the amount of lithium ions that can be received in and released from a positive electrode active material to achieve high capacity and high energy density of a secondary battery. A lithium manganese oxide particle includes a first region and a second region. The valence number of manganese in the first region is lower than the valence number of manganese in the second region. The lithium manganese oxide has high structural stability and high capacity characteristics.
    Type: Grant
    Filed: November 25, 2014
    Date of Patent: September 26, 2017
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takahiro Kawakami, Mayumi Mikami, Shunsuke Adachi, Shuhei Yoshitomi, Teruaki Ochiai, Yumiko Yoneda, Yohei Momma, Satoshi Seo
  • Publication number: 20170170466
    Abstract: A power storage device having high capacitance is provided. A power storage device with excellent cycle characteristics is provided. A power storage device with high charge and discharge efficiency is provided. A power storage device including a negative electrode with low resistance is provided. A negative electrode for a power storage device includes a number of composites in particulate forms. The composites include a negative electrode active material, a first functional material, and a compound. The compound includes a constituent element of the negative electrode active material and a constituent element of the first functional material. The negative electrode active material includes a region in contact with at least one of the first functional material or the compound.
    Type: Application
    Filed: December 9, 2016
    Publication date: June 15, 2017
    Inventors: Hiroyuki MIYAKE, Nobuhiro INOUE, Ryo YAMAUCHI, Mako MOTOYOSHI, Takahiro KAWAKAMI, Mayumi MIKAMI, Miku FUJITA, Shunpei YAMAZAKI
  • Publication number: 20160164089
    Abstract: The amount of lithium ions that can be received and released in and from a positive electrode active material is increased, and high capacity and high energy density of a secondary battery are achieved. Provided is a lithium-manganese composite oxide represented by LixMnyMzOw, where M is a metal element other than Li and Mn, or Si or P, and y, z, and w satisfy 0?x/(y+z)<2, y>0, z>0, 0.26?(y+z)/w<0.5, and 0.2<z/y<1.2. The lithium manganese composite oxide has high structural stability and high capacity.
    Type: Application
    Filed: February 10, 2016
    Publication date: June 9, 2016
    Inventors: Takahiro KAWAKAMI, Shuhei YOSHITOMI, Teruaki OCHIAI, Yumiko SAITO, Yohei MOMMA, Satoshi SEO, Mayumi MIKAMI, Shunsuke ADACHI
  • Patent number: 9293236
    Abstract: The amount of lithium ions that can be received and released in and from a positive electrode active material is increased, and high capacity and high energy density of a secondary battery are achieved. Provided is a lithium-manganese composite oxide represented by LixMnyMzOw, where M is a metal element other than Li and Mn, or Si or P, and y, z, and w satisfy 0?x/(y+z)<2, y>0, z>0, 0.26?(y+z)/w<0.5, and 0.2<z/y<1.2. The lithium manganese composite oxide has high structural stability and high capacity.
    Type: Grant
    Filed: June 30, 2014
    Date of Patent: March 22, 2016
    Assignee: SEMIDONCONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Takahiro Kawakami, Shuhei Yoshitomi, Teruaki Ochiai, Yumiko Saito, Yohei Momma, Satoshi Seo, Mayumi Mikami, Shunsuke Adachi
  • Publication number: 20160064154
    Abstract: A mixture of amorphous PAHs and at least one of a carrier ion storage metal, a Sn compound, a carrier ion storage alloy, a metal compound, Si, Sb, and SiO2 is used as the negative electrode active material. The theoretical capacity of amorphous PAHs greatly exceeds that of a graphite-based carbon material. Thus, the use of amorphous PAHs enables the negative electrode active material to have a higher capacity than in the case of using the graphite-based carbon material. Further, addition of at least one of the carrier ion storage metal, the Sn compound, the carrier ion storage alloy, the metal compound, Si, Sb, and SiO2 to the amorphous PAHs enables the negative electrode active material to have a higher capacity than the case of only using the amorphous PAHs.
    Type: Application
    Filed: November 11, 2015
    Publication date: March 3, 2016
    Inventors: Yumiko SAITO, Rie YOKOI, Mayumi MIKAMI
  • Patent number: 9064967
    Abstract: The semiconductor element includes an oxide semiconductor layer on an insulating surface; a source electrode layer and a drain electrode layer over the oxide semiconductor layer; a gate insulating layer over the oxide semiconductor layer, the source electrode layer, and the drain electrode layer; and a gate electrode layer over the gate insulating layer. The source electrode layer and the drain electrode layer have sidewalls which are in contact with a top surface of the oxide semiconductor layer.
    Type: Grant
    Filed: August 29, 2014
    Date of Patent: June 23, 2015
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hideomi Suzawa, Motomu Kurata, Mayumi Mikami
  • Publication number: 20150155556
    Abstract: To increase the amount of lithium ions that can be received in and released from a positive electrode active material to achieve high capacity and high energy density of a secondary battery. A lithium manganese oxide particle includes a first region and a second region. The valence number of manganese in the first region is lower than the valence number of manganese in the second region. The lithium manganese oxide has high structural stability and high capacity characteristics.
    Type: Application
    Filed: November 25, 2014
    Publication date: June 4, 2015
    Inventors: Takahiro KAWAKAMI, Mayumi MIKAMI, Shunsuke ADACHI, Shuhei YOSHITOMI, Teruaki OCHIAI, Yumiko YONEDA (Former: SAITO), Yohei MOMMA, Satoshi SEO
  • Publication number: 20150014605
    Abstract: The amount of lithium ions that can be received and released in and from a positive electrode active material is increased, and high capacity and high energy density of a secondary battery are achieved. Provided is a lithium-manganese composite oxide represented by LixMnyMzOw, where M is a metal element other than Li and Mn, or Si or P, and y, z, and w satisfy 0?x/(y+z)<2, y>0, z>0, 0.26?(y+z)/w<0.5, and 0.2<z/y<1.2. The lithium manganese composite oxide has high structural stability and high capacity.
    Type: Application
    Filed: June 30, 2014
    Publication date: January 15, 2015
    Inventors: Takahiro KAWAKAMI, Shuhei YOSHITOMI, Teruaki OCHIAI, Yumiko SAITO, Yohei MOMMA, Satoshi SEO, Mayumi MIKAMI, Shunsuke ADACHI
  • Publication number: 20140367678
    Abstract: The semiconductor element includes an oxide semiconductor layer on an insulating surface; a source electrode layer and a drain electrode layer over the oxide semiconductor layer; a gate insulating layer over the oxide semiconductor layer, the source electrode layer, and the drain electrode layer; and a gate electrode layer over the gate insulating layer. The source electrode layer and the drain electrode layer have sidewalls which are in contact with a top surface of the oxide semiconductor layer.
    Type: Application
    Filed: August 29, 2014
    Publication date: December 18, 2014
    Inventors: Hideomi Suzawa, Motomu Kurata, Mayumi Mikami
  • Patent number: 8901561
    Abstract: A first conductive film, a first insulating film, a semiconductor film, an impurity semiconductor film, a second conductive film, and a first resist mask are formed; first etching is performed to expose at least a surface of the first conductive film; second etching accompanied by side etching is performed on part of the first conductive film to form a gate electrode layer; a second resist mask is formed; third etching is performed to form a source and drain electrode layers, a source and drain regions, and a semiconductor layer; a second insulating film is formed; an opening portion is formed in the second insulating film to partially expose the source or drain electrode layer; a pixel electrode is selectively formed in the opening portion and over the second insulating film; and a supporting portion formed using the gate electrode layer is formed in a region overlapping with the opening portion.
    Type: Grant
    Filed: September 21, 2011
    Date of Patent: December 2, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takafumi Mizoguchi, Mayumi Mikami, Yumiko Saito
  • Patent number: 8865270
    Abstract: The power extraction efficiency of a nonaqueous electrolyte secondary battery such as a lithium ion battery is improved. A material having magnetic susceptibility anisotropy such as an olivine type oxide including a transition metal element is used for active material particles. The active material particles and an electrolyte solution are mixed to form a slurry. The slurry is applied to a current collector, and then the current collector is left in a magnetic field. Thus, the active material particles are oriented. With the use of active material particles oriented in such a manner, the power extraction efficiency can be improved.
    Type: Grant
    Filed: December 29, 2011
    Date of Patent: October 21, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Mayumi Mikami, Takuya Miwa, Kuniharu Nomoto, Takeshi Osada
  • Patent number: 8854583
    Abstract: In a liquid crystal display device in which a liquid crystal layer exhibiting a blue phase is sandwiched between a first substrate and a second substrate, a pixel electrode layer is electrically connected to a drain electrode layer of a transistor and a common electrode layer is electrically connected to a conductive layer formed through the same steps as the drain electrode layer. The pixel electrode layer and the common electrode layer are over an interlayer film and spaced apart from each other. An opening formed in the interlayer film is filled with liquid crystal, and the liquid crystal layer is formed.
    Type: Grant
    Filed: March 30, 2011
    Date of Patent: October 7, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Daisuke Kubota, Akio Yamashita, Tetsuji Ishitani, Tomohiro Tamura, Mayumi Mikami
  • Patent number: 8823074
    Abstract: The semiconductor element includes an oxide semiconductor layer on an insulating surface; a source electrode layer and a drain electrode layer over the oxide semiconductor layer; a gate insulating layer over the oxide semiconductor layer, the source electrode layer, and the drain electrode layer; and a gate electrode layer over the gate insulating layer. The source electrode layer and the drain electrode layer have sidewalls which are in contact with a top surface of the oxide semiconductor layer.
    Type: Grant
    Filed: August 1, 2013
    Date of Patent: September 2, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hideomi Suzawa, Motomu Kurata, Mayumi Mikami
  • Publication number: 20140027767
    Abstract: The semiconductor element includes an oxide semiconductor layer on an insulating surface; a source electrode layer and a drain electrode layer over the oxide semiconductor layer; a gate insulating layer over the oxide semiconductor layer, the source electrode layer, and the drain electrode layer; and a gate electrode layer over the gate insulating layer. The source electrode layer and the drain electrode layer have sidewalls which are in contact with a top surface of the oxide semiconductor layer.
    Type: Application
    Filed: August 1, 2013
    Publication date: January 30, 2014
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hideomi Suzawa, Motomu Kurata, Mayumi Mikami