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).

  • Publication number: 20240063387
    Abstract: A positive electrode active material having a high charge-discharge capacity and high safety and a secondary battery including the positive electrode active material are provided. The positive electrode active material includes lithium, a transition metal M, an additive element, and oxygen. The powder volume resistivity of the positive electrode active material is higher than or equal to 1.0×105 ?·cm at a temperature of higher than or equal to 180° C. and lower than or equal to 200° C. and at a pressure of higher than or equal to 0.3 MPa and lower than or equal to 2 MPa. The median diameter of the positive electrode active material is preferably greater than or equal to 3 ?m and less than or equal to 10 ?m.
    Type: Application
    Filed: August 14, 2023
    Publication date: February 22, 2024
    Inventors: Shunpei YAMAZAKI, Tetsuya KAKEHATA, Shuhei YOSHITOMI, Yohei MOMMA, Atsushi KAWATSUKI, Mayumi MIKAMI, Junya MARUYAMA, Akio ENDO, Kaori OGITA
  • Patent number: 11906594
    Abstract: An electric automobile incorporating a secondary battery has a disadvantage such as a difficulty in knowing the remaining capacity accurately and in predicting the time when the remaining capacity becomes zero because of deterioration of the secondary battery. The internal resistance is estimated with high accuracy even when the secondary battery deteriorates. Data used for learning or estimation is a data group (also referred to as data with regenerative charging) that is limited to data acquired within a certain time range around the end of regenerative charging. Such data within the limited range is extracted, used for learning, and subjected to the estimation. Thus, a value of the internal resistance can be output with high accuracy, specifically, with a mean error rate of 1% or less.
    Type: Grant
    Filed: May 15, 2020
    Date of Patent: February 20, 2024
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Jo Saito, Mayumi Mikami
  • Patent number: 11901548
    Abstract: A positive electrode active material, which has a high capacity and excellent charge and discharge cycle performance, for a lithium-ion secondary battery is provided. Alternatively, a positive electrode active material that inhibits a decrease in capacity in charge and discharge cycles when used in a lithium-ion secondary battery is provided. Alternatively, a high-capacity secondary battery is provided. Alternatively, a highly safe or reliable secondary battery is provided. The positive electrode active material contains a first substance including a first crack and a second substance positioned inside the first crack. The first substance contains one or more of cobalt, manganese, and nickel, lithium, oxygen, magnesium, and fluorine. The second substance contains phosphorus and oxygen.
    Type: Grant
    Filed: June 11, 2019
    Date of Patent: February 13, 2024
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Kazuhito Machikawa, Yohei Momma, Teruaki Ochiai, Mayumi Mikami
  • Publication number: 20240036117
    Abstract: A battery evaluation system that performs evaluation by easily linking a plurality of measurement methods relating to a secondary battery is provided. A charge and discharge device is configured to perform, in a first period, either or both of charge and discharge of a secondary battery. The first measurement device is configured to perform, in the first period, measurement of a spectrum a plurality of times. The arithmetic portion is configured to generate a first graph using the plurality of measured spectra. The arithmetic portion is configured to generate data of a second graph using a set of data including a voltage and the time of measurement of the voltage. A display portion is configured to display the first graph and the second graph at the same time. The battery evaluation system is configured to set a first area in one of the first graph and the second graph and to display a second area corresponding to the first area in the other of the first graph and the second graph.
    Type: Application
    Filed: July 27, 2023
    Publication date: February 1, 2024
    Inventors: Kazuki TANEMURA, Mayumi MIKAMI, Kazuki HIGASHI, Haruki KATAGIRI, Kyoichi MUKAO
  • Patent number: 11870042
    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: Grant
    Filed: August 28, 2018
    Date of Patent: January 9, 2024
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Mayumi Mikami, Ryota Tajima, Hideaki Shishido, Kensuke Yoshizumi
  • Patent number: 11843113
    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: Grant
    Filed: December 4, 2019
    Date of Patent: December 12, 2023
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takahiro Kawakami, Teruaki Ochiai, Yohei Momma, Ayae Tsuruta, Masahiro Takahashi, Mayumi Mikami
  • Publication number: 20230361267
    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: July 13, 2023
    Publication date: November 9, 2023
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yohei Momma, Mayumi MIKAMI, Aya UCHIDA, Kazuhito MACHIKAWA
  • Publication number: 20230343924
    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 30, 2023
    Publication date: October 26, 2023
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Publication number: 20230343952
    Abstract: A positive electrode active material with high charge and discharge capacity is provided. A positive electrode active material with high charge and discharge voltage is provided. A positive electrode active material that hardly deteriorates is provided. The positive electrode active material is formed through a plurality of heating steps. The second and subsequent heating steps are preferably performed at a temperature higher than or equal to 742° C. and lower than or equal to 920° C. for longer than or equal to an hour and shorter than or equal to 10 hours. Through the heating, magnesium, fluorine, and the like are distributed in a surface portion of the positive electrode active material with preferable concentrations. The crystal structure of general lithium cobalt oxide is easily broken because it becomes the H1-3 phase type crystal structure when being charged at 4.
    Type: Application
    Filed: June 15, 2021
    Publication date: October 26, 2023
    Inventors: Yohei MOMMA, Mayumi MIKAMI, Teruaki OCHIAI
  • Patent number: 11799080
    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: Grant
    Filed: May 11, 2018
    Date of Patent: October 24, 2023
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Mayumi Mikami, Aya Uchida, Yumiko Yoneda, Yohei Momma, Masahiro Takahashi, Teruaki Ochiai
  • Publication number: 20230335733
    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: April 25, 2023
    Publication date: October 19, 2023
    Inventors: Mayumi MIKAMI, Yohei MOMMA, Kazutaka KURIKI, Kazuhei NARITA
  • Publication number: 20230327088
    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: June 1, 2023
    Publication date: October 12, 2023
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Takahiro KAWAKAMI, Teruaki OCHIAI, Yohei MOMMA, Ayae TSURUTA, Masahiro Takahashi, Mayumi MIKAMI
  • Publication number: 20230327075
    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 1, 2023
    Publication date: October 12, 2023
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Publication number: 20230327073
    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 30, 2023
    Publication date: October 12, 2023
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Publication number: 20230317940
    Abstract: A secondary battery and a positive electrode active material each having high energy density per weight and per volume are provided. The secondary battery includes a positive electrode, the positive electrode includes lithium cobalt oxide, and the lithium cobalt oxide has a projection containing at least one or two or more selected from Hf, V, Nb, Ce, and Sm. The projection may further contain Mg, F, Ni, or Al as an additive element. The secondary battery is manufactured through a step of forming a mixed solution by mixing the lithium cobalt oxide and a metal alkoxide containing one or two or more selected from Hf, V, Nb, Ce, and Sm. With such a positive electrode active material, a secondary battery with a high charge voltage can be provided.
    Type: Application
    Filed: July 26, 2021
    Publication date: October 5, 2023
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Jo Saito, Yohei MOMMA, Teruaki OCHIAI, Yusuke YOSHITANI, Mayumi MIKAMI
  • Patent number: 11777089
    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: Grant
    Filed: April 26, 2022
    Date of Patent: October 3, 2023
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Mayumi Mikami, Aya Uchida, Yumiko Yoneda, Yohei Momma, Masahiro Takahashi, Teruaki Ochiai
  • Publication number: 20230299274
    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: May 25, 2023
    Publication date: September 21, 2023
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Takahiro KAWAKAMI, Teruaki OCHIAI, Yohei MOMMA, Ayae TSURUTA, Masahiro Takahashi, Mayumi MIKAMI
  • Publication number: 20230299265
    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 26, 2023
    Publication date: September 21, 2023
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Publication number: 20230290926
    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 22, 2023
    Publication date: September 14, 2023
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Publication number: 20230246198
    Abstract: A positive electrode for a secondary battery having excellent cycle performance is provided. The positive electrode for a secondary battery includes a positive electrode current collector layer, a base film, a positive electrode active material layer, and a cap layer; the base film contains titanium nitride; the positive electrode active material layer contains lithium cobalt oxide; and the cap layer contains titanium oxide. The use of titanium nitride for the base film can inhibit oxidation of the positive electrode current collector and diffusion of metal atoms while ensuring an adequate conductivity. The use of titanium oxide for the cap layer can inhibit a side reaction between the positive electrode active material layer and an electrolyte and collapse of a crystal structure of the electrode active material, improving the cycle performance.
    Type: Application
    Filed: September 29, 2020
    Publication date: August 3, 2023
    Inventors: Kaori OGITA, Hiroshi KADOMA, Tomoya HIROSE, Yumiko YONEDA, Yuji IWAKI, Tatsuyoshi TAKAHASHI, Shunpei YAMAZAKI, Mayumi MIKAMI, Kazuki TANEMURA