Patents by Inventor Kyoung Hwan Choi

Kyoung Hwan Choi 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: 6916764
    Abstract: Provided is a Pt—Ru based quaternary metal anode catalyst for a direct methanol fuel cell (DMFC). The Pt—Ru based quaternary metal anode catalyst has high activity to methanol oxidation and strong resistance to catalyst poisoning due to carbon monoxide (CO), which is a byproduct of the methanol oxidation. Therefore, the Pt—Ru based quaternary metal anode catalyst can give high power density and can replace existing commercial catalysts.
    Type: Grant
    Filed: September 13, 2002
    Date of Patent: July 12, 2005
    Assignee: Samsung SDI Co., Ltd.
    Inventors: Kyoung Hwan Choi, Seol-ah Lee, Yung-eun Sung, Kyung-won Park, Jong-ho Choi
  • Publication number: 20050074652
    Abstract: A direct liquid feed fuel cell stack that includes Membrane Electrode Assemblies (MEAs) and bipolar plates. Each MEA includes an electrolyte membrane, an anode and a cathode, and the MEA is interposed between stacked bipolar plates. Each bipolar plate includes a groove with a predetermined depth enclosing an electrode region on each face of the bipolar plate, and a plurality of fuel flow holes in the electrode region to supply fuel or oxidant to a corresponding fuel channel, with a sealing member being formed on the groove. The direct liquid feed fuel cell stack prevents fuel leakage and useless fuel consumption, thereby providing longer hours of operation.
    Type: Application
    Filed: August 11, 2004
    Publication date: April 7, 2005
    Applicant: SAMSUNG SDI CO., LTD.
    Inventor: Kyoung-hwan Choi
  • Publication number: 20050069736
    Abstract: A fuel supply device for direct methanol fuel cells includes a fuel tank for storing liquid fuel, a wick structure formed on the fuel tank, the wick structure for receiving the liquid fuel from the fuel tank, a sheet stack disposed on the wick structure, the sheet stack for absorbing and transferring, in an upward direction, the liquid fuel supplied to the wick structure, and an electrode plate disposed on the sheet stack for supplying, in an upward direction, the liquid fuel absorbed into the sheet stack. The fuel supply device may continuously and uniformly supply a proper amount of liquid fuel and effectively remove by-products generated in a fuel cell. Thus, a long life, efficient fuel cell may be created with the fuel supply device.
    Type: Application
    Filed: September 2, 2004
    Publication date: March 31, 2005
    Inventors: Jung-min Oh, Hye-jung Cho, Kyoung-hwan Choi
  • Publication number: 20050069754
    Abstract: A diffusion electrode for a fuel cell, having good polar liquid transporting property and gas transporting property, and an electrode and a fuel cell using the diffusion electrode are provided. The diffusion electrode includes: hydrophobic porous agglomerates containing electroconductive particles and a hydrophobic binder resin, wherein the hydrophobic porous agglomerates form a three dimensional netlike structure; and hydrophilic porous agglomerates containing electroconductive particles, wherein the hydrophilic porous agglomerates form a three dimensional netlike structure filling empty space among the three dimensional netlike structure formed by the hydrophobic porous agglomerates..
    Type: Application
    Filed: September 17, 2004
    Publication date: March 31, 2005
    Inventors: Ji-rae Kim, Kyoung-hwan Choi
  • Publication number: 20040202906
    Abstract: A fuel amount control system of a fuel cell includes a fuel storage unit that stores the fuel to be supplied to the anode, a diluent storage unit that stores a diluent generated as a result of the chemical reaction in the cathode, a fuel mixing unit that mixes the fuel supplied from the fuel storage unit and the diluent supplied from the diluent storage unit to supply a fuel mixture solution to the anode, a sensor located inside the fuel mixing unit, which has a various volume that depends on the concentration of the fuel in the fuel mixture solution and outputs an electrical signal according to a volume variation, and a control unit that receives the electrical signal output from the sensor and outputs electrical signals to open and close the fuel storage unit and the diluent storage unit such that the fuel mixture solution having an appropriate concentration is supplied from the fuel mixing unit to the fuel cell stack.
    Type: Application
    Filed: April 9, 2004
    Publication date: October 14, 2004
    Applicant: Samsung SDI Co., Ltd.
    Inventors: Hae-Kyoung Kim, Kyoung-Hwan Choi
  • Publication number: 20040191606
    Abstract: A bipolar plate and a fuel cell using the same are provided. The bipolar plate includes a flow field that has a length between three and eight times greater than the square of the area of the bipolar plate. The fuel cell includes a first bipolar plate in which a fuel flow field having a length that is between three and eight times greater than the square of the area of the first bipolar plate is formed, and a second bipolar plate in which an air flow field having a length that is between three and eight times greater than the spare of the area of the second bipolar plate is formed. The fuel cell has a lower, uniform internal pressure and can produce a greater power.
    Type: Application
    Filed: February 6, 2004
    Publication date: September 30, 2004
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Seung Jae Lee, Kyoung Hwan Choi, Hyuk Chang
  • Patent number: 6689502
    Abstract: A monopolar cell pack for a direct methanol fuel cell is provided. In the monopolar cell pack, series-connection of electrodes makes it unnecessary for connections to pass through an electrolyte membrane and allows single cells to be electrically connected on the first and second surfaces of the ion exchange membrane, respectively, thereby preventing leakage of fuel. As a result, the internal electric circuit according to the present invention can be simplified. Also, since current collectors contact the anodes and cathodes entirely rather than partially, contact resistance can be considerably reduced, thereby greatly reducing a loss due to resistance. Carbon dioxide, which is a byproduct of the reaction, can be easily exhausted through an exhaust path installed in each current collector, thereby improving performance of a cell pack.
    Type: Grant
    Filed: November 21, 2001
    Date of Patent: February 10, 2004
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Kyoung-hwan Choi
  • Publication number: 20030198853
    Abstract: Provided is an air breathing direct methanol fuel cell pack including membrane electrode assemblies (MEAs) forming a plurality of single cells having an electrolyte membrane, a plurality of anodes on a first plane of the electrolyte membrane and a plurality of cathodes on a second plane of the electrolyte membrane correspondingly to the anodes, the second plane being opposed to the first plane, a fuel supply unit storing fuel fed to the anodes and having fuel supply plates with a plurality of fuel supply holes through which the fuel passes, and wicking sheets provided along a fuel supply path between the fuel supply plates and the MEAs, diffusing the fuel supplied through the fuel supply plates to supply the fuel to the anodes of the MEAs. fuel can be evenly supplied throughout MEAs, thereby attaining uniform power output, irrespective of a use posture of a cell pack.
    Type: Application
    Filed: September 30, 2002
    Publication date: October 23, 2003
    Applicant: Samsung SDI Co., Ltd.
    Inventors: Kyoung Hwan Choi, Hyuk Chang
  • Publication number: 20030180594
    Abstract: Provided is an air breathing direct methanol fuel cell pack including a membrane electrode assembly (MEA) forming a plurality of single cells having an electrolyte membrane, a plurality of anodes on a first plane of the electrolyte membrane and a plurality of cathodes on a second plane of the electrolyte membrane correspondingly to the anodes, the second plane being opposed to the first plane, a fuel supply unit facing the first plane of the MEA and supplying liquid fuel to the anodes on the first plane of the MEA, an upper panel member facing the second plane of the MEA and having a plurality of air vent holes through which air passes and a plurality of air channels for mutually connecting inner parts of the air vent holes, the air channels formed at the internal surface facing the MEA, current collectors provided on the cathode and anode of each single cell in the MEA, conductors electrically connecting the current collectors to form electric circuitry among the single cells, and a lower panel member for fo
    Type: Application
    Filed: September 30, 2002
    Publication date: September 25, 2003
    Applicant: Samsung SDI Co. Ltd.
    Inventors: Kyoung Hwan Choi, Hyuk Chang
  • Publication number: 20030157393
    Abstract: Provided is a Pt—Ru based quaternary metal anode catalyst for a direct methanol fuel cell (DMFC). The Pt—Ru based quaternary metal anode catalyst has high activity to methanol oxidation and strong resistance to catalyst poisoning due to carbon monoxide (CO), which is a byproduct of the methanol oxidation.
    Type: Application
    Filed: September 13, 2002
    Publication date: August 21, 2003
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Kyoung Hwan Choi, Seol-Ah Lee, Yung-Eun Sung, Kyung-Won Park, Jong-Ho Choi
  • Publication number: 20020142205
    Abstract: Provided a proton exchange membrane fuel cell (PEMFC) stack with at least two cell units. Each cell unit includes: a catalyzed membrane formed by catalyzing both surfaces of an electrolyte layer; a fuel flow field portion and air flow field portion formed at opposite surfaces of the catalyzed membrane, at least one of the fuel and air flow field portions comprising a parallel flow field which induces gas flow in a direction parallel to the surface of the catalyzed membrane and an orthogonal flow field which induces gas flow in a direction orthogonal to the surface of the catalyzed membrane; a bipolar plate in contact with each outer surface of the fuel flow region portion and the air flow region portions. The volume and weight of the entire fuel cell stack can be flexibly reduced by adjusting the number of cell units. In addition, a defective cell unit can be easily replaced without performance degradation in the cell stack. The use of bipolar plates as electrodes promotes gas flow.
    Type: Application
    Filed: March 28, 2002
    Publication date: October 3, 2002
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Ji-Rae Kim, Kyoung-Hwan Choi
  • Publication number: 20020132151
    Abstract: A monopolar cell pack for a direct methanol fuel cell is provided. In the monopolar cell pack, series-connection of electrodes makes it unnecessary for connections to pass through an electrolyte membrane and allows single cells to be electrically connected on the first and second surfaces of the ion exchange membrane, respectively, thereby preventing leakage of fuel. As a result, the internal electric circuit according to the present invention can be simplified. Also, since current collectors contact the anodes and cathodes entirely rather than partially, contact resistance can be considerably reduced, thereby greatly reducing a loss due to resistance. Carbon dioxide, which is a byproduct of the reaction, can be easily exhausted through an exhaust path installed in each current collector, thereby improving performance of a cell pack.
    Type: Application
    Filed: November 21, 2001
    Publication date: September 19, 2002
    Inventor: Kyoung-Hwan Choi