Patents by Inventor Tomofumi YOKOYAMA

Tomofumi YOKOYAMA 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: 10998576
    Abstract: An electrolyte precursor solution includes a metallic compound containing elements constituting an electrolyte, a solvent capable of dissolving the metallic compound, and an anionic surfactant having a sulfate group (SO42?) bonded to a hydrophobic group R. By reacting such an electrolyte precursor solution with active material particles containing lithium, lithium sulfate derived from the anionic surfactant is interposed at the interface between the surface of the active material particle and the electrolyte so as to enhance the dissociation of lithium ions at the interface, and thus, an excellent ion conductivity can be realized.
    Type: Grant
    Filed: December 21, 2018
    Date of Patent: May 4, 2021
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Hitoshi Yamamoto, Tomofumi Yokoyama
  • Patent number: 10947160
    Abstract: A solid electrolyte capable of securing grain boundary resistance even when sintering is performed at a relatively low temperature and a lithium ion battery using the solid electrolyte are provided. The solid electrolyte includes a first electrolyte which contains a lithium composite metal compound containing one kind of first metal element selected from group 13 elements in period 3 or higher, and a second electrolyte which contains Li and at least two kinds of second metal elements selected from group 5 elements in period 5 or higher or group 15 elements in period 5 or higher.
    Type: Grant
    Filed: August 13, 2020
    Date of Patent: March 16, 2021
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Hitoshi Yamamoto, Tomofumi Yokoyama
  • Patent number: 10862162
    Abstract: An electrode composite body includes: an active material molded body including active material particles which include a lithium composite oxide and have a particle shape, and a communication hole that is provided between the active material particles; a first solid electrolyte layer that is provided on a surface of the active material molded body, and includes a first inorganic solid electrolyte; and a second solid electrolyte layer that is provided on the surface of the active material molded body, and includes a second inorganic solid electrolyte of which a composition is different from a composition of the first inorganic solid electrolyte, and which contains boron as a constituent element and is amorphous.
    Type: Grant
    Filed: October 16, 2019
    Date of Patent: December 8, 2020
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Tsutomu Teraoka, Tomofumi Yokoyama, Hitoshi Yamamoto
  • Publication number: 20200369574
    Abstract: A solid electrolyte capable of securing grain boundary resistance even when sintering is performed at a relatively low temperature and a lithium ion battery using the solid electrolyte are provided. The solid electrolyte includes a first electrolyte which contains a lithium composite metal compound containing one kind of first metal element selected from group 13 elements in period 3 or higher, and a second electrolyte which contains Li and at least two kinds of second metal elements selected from group 5 elements in period 5 or higher or group 15 elements in period 5 or higher.
    Type: Application
    Filed: August 13, 2020
    Publication date: November 26, 2020
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Hitoshi YAMAMOTO, Tomofumi YOKOYAMA
  • Publication number: 20200358135
    Abstract: A manufacturing method of an electrode assembly capable of easily manufacturing a configuration in which an electrolyte and an active material are bonded to each other. A step of supplying, solidifying, and crystallizing a solid electrolyte including Li2+XC1?XBXO3 (X represents a real number equal to or greater than 0 and smaller than 1), so as to be in contact with an active material aggregate including a communication hole between active material particles, is included. In a case where the solid electrolyte is melted, the solid electrolyte is heated in a range of 650 degrees to 900 degrees.
    Type: Application
    Filed: July 28, 2020
    Publication date: November 12, 2020
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Tsutomu TERAOKA, Tomofumi YOKOYAMA, Hitoshi YAMAMOTO, Tomoyuki OKUYAMA
  • Patent number: 10826116
    Abstract: A solid electrolyte which reduces grain boundary resistance and exhibits a high total ion conductivity is provided. The solid electrolyte includes a first area which has a cubic garnet type crystalline and a second area which is amorphous, around the first area, in which each of the first area and the second area contains a composite oxide represented by formula (1) or (2) as a forming material, and an abundance ratio of metal atoms each having an ionic radius of 78 pm or more gradually increases from the first area to the second area. Li7+xLa3?xZr2AxO12??(1) [In formula (1), A is at least one selected from the group consisting of Mg, Ca, Sr, and Ba. In addition, x is 0.1 or more and 0.6 or less.] Li7La3?xZr2BxO12??(2) [In formula (2), B is at least one selected from the group consisting of Sc and Y. In addition, x is 0.1 or more and 0.6 or less.
    Type: Grant
    Filed: March 3, 2017
    Date of Patent: November 3, 2020
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Hitoshi Yamamoto, Tomofumi Yokoyama
  • Patent number: 10784534
    Abstract: A solid electrolyte capable of securing grain boundary resistance even when firing is performed at a relatively low temperature and a battery using the solid electrolyte are provided. The solid electrolyte includes a first electrolyte which contains a lithium composite metal compound, and a second electrolyte which contains Li and at least two kinds of metal elements selected from group 5 elements in period 5 or higher or group 15 elements in period 5 or higher.
    Type: Grant
    Filed: March 10, 2017
    Date of Patent: September 22, 2020
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Tomofumi Yokoyama, Hitoshi Yamamoto
  • Patent number: 10774004
    Abstract: A solid electrolyte capable of securing grain boundary resistance even when sintering is performed at a relatively low temperature and a lithium ion battery using the solid electrolyte are provided. The solid electrolyte includes a first electrolyte which contains a lithium composite metal compound containing one kind of first metal element selected from group 13 elements in period 3 or higher, and a second electrolyte which contains Li and at least two kinds of second metal elements selected from group 5 elements in period 5 or higher or group 15 elements in period 5 or higher.
    Type: Grant
    Filed: March 13, 2017
    Date of Patent: September 15, 2020
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Hitoshi Yamamoto, Tomofumi Yokoyama
  • Patent number: 10770757
    Abstract: A manufacturing method of an electrode assembly capable of easily manufacturing a configuration in which an electrolyte and an active material are bonded to each other is provided. A step of supplying, solidifying, and crystallizing a solid electrolyte 22 including Li2+XC1?XBXO3 (X represents a real number equal to or greater than 0 and smaller than 1), so as to be in contact with an active material aggregate 12 including a communication hole 14 between active material particles 13, is included. In a case where the solid electrolyte 22 is melted, the solid electrolyte 22 is heated in a range of 650 degrees to 900 degrees.
    Type: Grant
    Filed: September 26, 2016
    Date of Patent: September 8, 2020
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Tsutomu Teraoka, Tomofumi Yokoyama, Hitoshi Yamamoto, Tomoyuki Okuyama
  • Patent number: 10756329
    Abstract: A lithium battery as a secondary battery has a battery cell including a first current collector which has a first face and a second face, a positive electrode active material particle which pierces the first current collector and is exposed from the first face and the second face, an electrolyte layer which covers the positive electrode active material particle exposed from the first face and the second face of the first current collector, a negative electrode as an electrode which is in contact with the electrolyte layer, and a second current collector which is in contact with the negative electrode. The battery cell is hermetically enclosed in a package in a state where one end portion which is a portion of the first current collector is exposed.
    Type: Grant
    Filed: October 29, 2018
    Date of Patent: August 25, 2020
    Assignee: SEIKO EPSON CORPORATION
    Inventor: Tomofumi Yokoyama
  • Publication number: 20200194824
    Abstract: A composite body includes an electrolyte which contains Li, La, Zr, O, and Ga; and an active material coated with barium titanate (BaTiO3) or lithium niobate (LiNbO3).
    Type: Application
    Filed: February 25, 2020
    Publication date: June 18, 2020
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Hitoshi YAMAMOTO, Tomofumi YOKOYAMA
  • Publication number: 20200176772
    Abstract: An active material includes a first oxide that is a composite metal oxide containing lithium and one or more types of elements selected from the group consisting of nickel, manganese, and cobalt, and a second oxide represented by the following formula (1), wherein the second oxide is formed in portions of a surface and an inside of the first oxide: LipNixMn2?x?yCOyO2?qFq (1). In the formula (1), p, q, x, and y are real numbers satisfying 0.98?p?1.07, 0<q?0.35, 0?x?1, and 0?y?1, respectively.
    Type: Application
    Filed: November 27, 2019
    Publication date: June 4, 2020
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Hitoshi YAMAMOTO, Tomofumi YOKOYAMA
  • Publication number: 20200168946
    Abstract: A lithium battery as a secondary battery includes a positive electrode composite material containing a solid electrolyte and a positive electrode active material containing lithium, a negative electrode as an electrode provided at one face of the positive electrode composite material, and a current collector provided at another face of the positive electrode composite material, wherein the solid electrolyte is a garnet-type fluorine-containing lithium composite metal oxide that is represented by the following compositional formula (1) or (2) and that conducts lithium. (Li7?3xGax) (La3?yNdy)Zr2O12?zFz ??(1) (Li7?3x+yGax) (La3?yCay) Zr2O12?zFz ??(2) Provided that 0.1?x?1.0, 0<y?0.2, and 0<z?1.0.
    Type: Application
    Filed: November 27, 2019
    Publication date: May 28, 2020
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Hitoshi YAMAMOTO, Tomofumi YOKOYAMA
  • Publication number: 20200144663
    Abstract: A composition for forming a lithium reduction resistant layer includes a solvent, and a lithium compound, a lanthanum compound, a zirconium compound, and a compound containing a metal M, each of which shows solubility in the solvent, and in which with respect to the stoichiometric composition of a compound represented by the general formula (I), the lithium compound is contained in an amount 1.05 times or more and 2.50 times or less, the lanthanum compound and the zirconium compound are contained in an amount 0.70 times or more and 1.00 times or less, and the compound containing a metal M is contained in an equal amount.
    Type: Application
    Filed: December 19, 2019
    Publication date: May 7, 2020
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Hitoshi YAMAMOTO, Tomofumi YOKOYAMA
  • Publication number: 20200127326
    Abstract: A secondary battery according to the present disclosure includes a solid electrolyte portion containing a lithium composite metal oxide represented by the following compositional formula (1), and current collectors disposed opposite to each other through the solid electrolyte portion: Li7-xLa3Zr2?(x+y)MaxMbyO12??(1) provided that 0.5<x+y<1.2 and (ix+jy)+4(x+y)>8 wherein i is an oxidation number of Ma and j is an oxidation number of Mb are satisfied, and Ma represents one or more types of Sb, Bi, Ce, Mn, V, Te, Tc, and Sn, and Mb represents one or more types of Nb, Cr, Mo, W, Ta, and Ti.
    Type: Application
    Filed: October 22, 2019
    Publication date: April 23, 2020
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Tomofumi YOKOYAMA
  • Patent number: 10615451
    Abstract: An electrolyte according to the invention includes a crystalline first electrolyte portion which contains a lithium composite metal oxide represented by the compositional formula (1). (Li7?3xGax)(La3?yNdy)Zr2O12??(1) In the formula, x and y satisfy the following formulae: 0.1?x?1.0 and 0.01?y?0.2.
    Type: Grant
    Filed: February 15, 2019
    Date of Patent: April 7, 2020
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Hitoshi Yamamoto, Tomofumi Yokoyama
  • Publication number: 20200052329
    Abstract: An electrode composite body includes: an active material molded body including active material particles which include a lithium composite oxide and have a particle shape, and a communication hole that is provided between the active material particles; a first solid electrolyte layer that is provided on a surface of the active material molded body, and includes a first inorganic solid electrolyte; and a second solid electrolyte layer that is provided on the surface of the active material molded body, and includes a second inorganic solid electrolyte of which a composition is different from a composition of the first inorganic solid electrolyte, and which contains boron as a constituent element and is crystalline.
    Type: Application
    Filed: October 16, 2019
    Publication date: February 13, 2020
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Tsutomu TERAOKA, Tomofumi Yokoyama, Hitoshi Yamamoto
  • Publication number: 20200052328
    Abstract: An electrode composite body includes: an active material molded body including active material particles which include a lithium composite oxide and have a particle shape, and a communication hole that is provided between the active material particles; a first solid electrolyte layer that is provided on a surface of the active material molded body, and includes a first inorganic solid electrolyte; and a second solid electrolyte layer that is provided on the surface of the active material molded body, and includes a second inorganic solid electrolyte of which a composition is different from a composition of the first inorganic solid electrolyte, and which contains boron as a constituent element and is amorphous.
    Type: Application
    Filed: October 16, 2019
    Publication date: February 13, 2020
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Tsutomu TERAOKA, Tomofumi YOKOYAMA, Hitoshi YAMAMOTO
  • Patent number: 10468717
    Abstract: An electrolyte includes a first electrolyte, in which an element constituting a crystalline lithium composite metal oxide represented by the following compositional formula (1) is substituted with a first metal element having a crystal radius of 78 pm or more, and an amorphous second electrolyte, which contains Li and a second metal element contained in the first electrolyte other than Li. (Li7?3x+yGax)(La3?yCay)Zr2O12??(1) (In the formula (1), x and y satisfy the following formulae: 0.1?x?0.6 and 0.0<y?0.3).
    Type: Grant
    Filed: June 1, 2018
    Date of Patent: November 5, 2019
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Hitoshi Yamamoto, Tomofumi Yokoyama
  • Patent number: 10454136
    Abstract: A polymer electrolyte according to the invention is represented by the following formula (1). In the formula (1), R1 and R2 are each independently hydrogen or CH3, R3 is any of C2H4, CH(CH3)CH2, and (CH2)3, m and n are each a copolymerization ratio of a structural unit in parentheses, and when m and n are set as follows: m+n=10, m and n satisfy the following formulae: 1?m?5 and 5?n?9, and p is 2 or more and 8 or less.
    Type: Grant
    Filed: December 14, 2017
    Date of Patent: October 22, 2019
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Hitoshi Yamamoto, Tomofumi Yokoyama