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: 11043660
    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: Grant
    Filed: July 8, 2020
    Date of Patent: June 22, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Teruaki Ochiai, Takahiro Kawakami, Mayumi Mikami, Yohei Momma, Masahiro Takahashi, Ayae Tsuruta
  • Publication number: 20210184214
    Abstract: A conduction path in an all-solid-state secondary battery is difficult to keep with a volume change in an active material due to charging and discharging in some cases. A positive electrode active material with a small volume change between the charged state and the discharged state is used for an all-solid-state secondary battery. For example, a positive electrode active material that has a layered rock-salt crystal structure in the discharged state and a crystal structure similar to the cadmium chloride type crystal structure in the charged state with a depth of charge of approximately 0.8 changes less in its volume and crystal structure between charging and discharging than known positive electrode active materials.
    Type: Application
    Filed: November 16, 2018
    Publication date: June 17, 2021
    Inventors: Mayumi MIKAMI, Yohei MOMMA, Kazutaka KURIKI, Kazuhei NARITA
  • Publication number: 20210143404
    Abstract: A method for manufacturing a lithium-ion secondary battery more safely at a lower cost is provided. A method for manufacturing a positive electrode for a secondary battery includes a step of forming slurry by mixing graphene oxide, a binder, and a positive electrode active material in a solvent containing water; a step of applying the slurry on a positive electrode current collector; and a step of reducing graphene oxide by at least one of chemical reduction and thermal reduction. As a reducing agent for the chemical reduction, ascorbic acid can be used.
    Type: Application
    Filed: November 2, 2020
    Publication date: May 13, 2021
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Mayumi MIKAMI, Kazuhei NARITA, Teruaki OCHIAI, Yumiko YONEDA
  • Patent number: 10998141
    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: Grant
    Filed: April 6, 2020
    Date of Patent: May 4, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yumiko Saito, Rie Yokoi, Mayumi Mikami
  • Publication number: 20210083281
    Abstract: A positive electrode active material having high capacity and excellent cycle performance is provided. The positive electrode active material has a small difference in a crystal structure between the charged state and the discharged state. For example, the crystal structure and volume of the positive electrode active material, which has a layered rock-salt crystal structure in the discharged state and a pseudo-spinel crystal structure in the charged state at a high voltage of approximately 4.6 V, are less likely to be changed by charge and discharge as compared with those of a known positive electrode active material.
    Type: Application
    Filed: May 11, 2018
    Publication date: March 18, 2021
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Mayumi MIKAMI, Aya UCHIDA, Yumiko YONEDA, Yohei MOMMA, Masahiro TAKAHASHI, Teruaki OCHIAI
  • Publication number: 20210028456
    Abstract: A positive electrode active material has a small difference in a crystal structure between the charged state and the discharged state. For example, the crystal structure and volume of the positive electrode active material, which has a layered rock-salt crystal structure in the discharged state and a pseudo-spinel crystal structure in the charged state at a high voltage of approximately 4.6 V, are less likely to be changed by charging and discharging as compared with those of a known positive electrode active material. In order to form the positive electrode active material having the pseudo-spinel crystal structure in the charged state, it is preferable that a halogen source such as a fluorine and a magnesium source be mixed with particles of a composite oxide containing lithium, a transition metal, and oxygen, which is synthesized in advance, and then the mixture be heated at an appropriate temperature for an appropriate time.
    Type: Application
    Filed: September 29, 2020
    Publication date: January 28, 2021
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Masahiro TAKAHASHI, Mayumi MIKAMI, Yohei MOMMA, Teruaki OCHIAI, Jyo SAITOU
  • Publication number: 20210020928
    Abstract: A negative electrode active material with high capacity and excellent cycle performance and rate performance is provided. In addition, a secondary battery including the negative electrode active material, and an electronic device including the secondary battery are provided. Nanosilicon is mixed with a solid electrolyte containing lithium, titanium, phosphorus, and oxygen, and graphene oxide is further added thereto. Then, graphene oxide contained in the mixture is reduced with ethanol in which ascorbic acid and lithium hydroxide hydrate are dissolved, so that the negative electrode active material is manufactured.
    Type: Application
    Filed: March 26, 2019
    Publication date: January 21, 2021
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Mayumi MIKAMI, Jun ISHIKAWA, Miku FUJITA, Kazuhei NARITA
  • Publication number: 20210020935
    Abstract: A positive electrode active material has a small difference in a crystal structure between the charged state and the discharged state. For example, the crystal structure and volume of the positive electrode active material, which has a layered rock-salt crystal structure in the discharged state and a pseudo-spinel crystal structure in the charged state at a high voltage of approximately 4.6 V, are less likely to be changed by charging and discharging as compared with those of a known positive electrode active material. In order to form the positive electrode active material having the pseudo-spinel crystal structure in the charged state, it is preferable that a halogen source such as a fluorine and a magnesium source be mixed with particles of a composite oxide containing lithium, a transition metal, and oxygen, which is synthesized in advance, and then the mixture be heated at an appropriate temperature for an appropriate time.
    Type: Application
    Filed: September 29, 2020
    Publication date: January 21, 2021
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Masahiro TAKAHASHI, Mayumi MIKAMI, Yohei MOMMA, Teruaki OCHIAI, Jyo SAITOU
  • Publication number: 20210020910
    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: October 7, 2020
    Publication date: January 21, 2021
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Publication number: 20200388888
    Abstract: A sensor element with excellent characteristics is provided. An electronic device including a power storage system with excellent characteristics is provided. A vehicle including a power storage system with excellent characteristics is provided. A novel semiconductor device is provided. The power storage system includes a storage battery, a neural network, and a sensor element; the neural network includes an input layer, an output layer, and one or a plurality of middle layers provided between the input layer and the output layer; a value corresponding to a first signal output from the sensor element is supplied to the input layer; the first signal is an analog signal; the sensor element includes a region in contact with a surface of the storage battery; and the sensor element has a function of measuring one or both of strain and temperature.
    Type: Application
    Filed: August 28, 2018
    Publication date: December 10, 2020
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Mayumi MIKAMI, Ryota TAJIMA, Hideaki SHISHIDO, Kensuke YOSHIZUMI
  • Publication number: 20200343529
    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: July 8, 2020
    Publication date: October 29, 2020
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Publication number: 20200343530
    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: July 8, 2020
    Publication date: October 29, 2020
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Publication number: 20200328402
    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 29, 2020
    Publication date: October 15, 2020
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Publication number: 20200313228
    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: June 15, 2020
    Publication date: October 1, 2020
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Ayae TSURUTA, Masahiro TAKAHASHI
  • Publication number: 20200295349
    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: May 28, 2020
    Publication date: September 17, 2020
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Patent number: 10741828
    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: Grant
    Filed: June 30, 2017
    Date of Patent: August 11, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Teruaki Ochiai, Takahiro Kawakami, Mayumi Mikami, Yohei Momma, Masahiro Takahashi, Ayae Tsuruta
  • Publication number: 20200234893
    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: April 6, 2020
    Publication date: July 23, 2020
    Inventors: Yumiko SAITO, Rie YOKOI, Mayumi MIKAMI
  • Publication number: 20200176770
    Abstract: A positive electrode active material has a small difference in a crystal structure between the charged state and the discharged state. For example, the crystal structure and volume of the positive electrode active material, which has a layered rock-salt crystal structure in the discharged state and a pseudo-spinel crystal structure in the charged state at a high voltage of approximately 4.6 V, are less likely to be changed by charging and discharging as compared with those of a known positive electrode active material. In order to form the positive electrode active material having the pseudo-spinel crystal structure in the charged state, it is preferable that a halogen source such as a fluorine and a magnesium source be mixed with particles of a composite oxide containing lithium, a transition metal, and oxygen, which is synthesized in advance, and then the mixture be heated at an appropriate temperature for an appropriate time.
    Type: Application
    Filed: June 14, 2018
    Publication date: June 4, 2020
    Inventors: Masahiro TAKAHASHI, Mayumi MIKAMI, Yohei MOMMA, Teruaki OCHIAI, Jyo SAITOU
  • Publication number: 20200152961
    Abstract: To provide a positive electrode active material with which the cycle performance of a secondary battery can be improved and a manufacturing method thereof. When a secondary battery is fabricated using, for a positive electrode, a positive electrode active material obtained by depositing a solid electrolyte on a lithium compound with the use of a graphene compound by spray-drying treatment and volatilizing carbon from the graphene compound by heat treatment, the decomposition of an electrolyte solution in contact with the positive electrode active material can be inhibited, contributing to improvement in the cycle performance of the secondary battery.
    Type: Application
    Filed: April 19, 2018
    Publication date: May 14, 2020
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yohei MOMMA, Mayumi MIKAMI, Aya UCHIDA, Kazuhito MACHIKAWA
  • Patent number: 10614967
    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: Grant
    Filed: November 11, 2015
    Date of Patent: April 7, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yumiko Saito, Rie Yokoi, Mayumi Mikami