Patents by Inventor Porter Mitchell

Porter Mitchell 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: 7384433
    Abstract: A compressible and deformable layer is densified and laminated to a layer of a material that is relatively resistant to stretching. The densification and bonding take place in a single step. As used in fabrication of electrodes, for example, electrodes for double layer capacitors, a deformable and compressible active electrode film is manufactured from activated carbon, conductive carbon, and a polymer. The electrode film may be bonded directly to a collector. Alternatively, a collector may be coated with a wet adhesive layer. The adhesive layer is subsequently dried onto the foil. The dried adhesive and foil combination may be manufactured as a product for later sale or use, and may be stored as such on a storage roll or other storage device. The active electrode film is overlayed on the metal foil, and processed in a laminating device, such as a calender. Lamination both densifies the active electrode film and bonds the film to the metal foil.
    Type: Grant
    Filed: July 28, 2004
    Date of Patent: June 10, 2008
    Assignee: Maxwell Technologies, Inc.
    Inventors: Porter Mitchell, Xiaomei Xi, Linda Zhong
  • Publication number: 20080117565
    Abstract: An inexpensive and reliable dry process based capacitor and method for making a self-supporting dry electrode film for use therein is disclosed. Also disclosed is an exemplary process for manufacturing an electrode for use in an energy storage device product, the process comprising: supplying dry carbon particles; supplying dry binder; dry mixing the dry carbon particles and dry binder; and dry fibrillizing the dry binder to create a matrix within which to support the dry carbon particles as dry material.
    Type: Application
    Filed: January 31, 2008
    Publication date: May 22, 2008
    Applicant: Maxwell Technologies, Inc.
    Inventors: Linda Zhong, Xiaomei Xi, Porter Mitchell, Bin Zou
  • Publication number: 20080117564
    Abstract: An inexpensive and reliable dry process based capacitor and method for making a self-supporting dry electrode film for use therein is disclosed. Also disclosed is an exemplary process for manufacturing an electrode for use in an energy storage device product, the process comprising: supplying dry carbon particles; supplying dry binder; dry mixing the dry carbon particles and dry binder; and dry fibrillizing the dry binder to create a matrix within which to support the dry carbon particles as dry material.
    Type: Application
    Filed: January 31, 2008
    Publication date: May 22, 2008
    Applicant: Maxwell Technologies, Inc.
    Inventors: Linda Zhong, Xiaomei Xi, Porter Mitchell, Bin Zou
  • Publication number: 20080102371
    Abstract: A dry process based capacitor and method for a self-supporting dry adhesive electrode film for use therein is disclosed.
    Type: Application
    Filed: November 13, 2007
    Publication date: May 1, 2008
    Applicant: Maxwell Technologies, Inc.
    Inventors: Porter Mitchell, Xiaomei Xi, Linda Zhong, Bin Zou
  • Publication number: 20080092808
    Abstract: A dry process based capacitor and method for a self-supporting dry adhesive electrode film for use therein is disclosed.
    Type: Application
    Filed: October 24, 2007
    Publication date: April 24, 2008
    Applicant: MAXWELL TECHNOLOGIES, INC.
    Inventors: Porter Mitchell, Xiaomei Xi, Linda Zhong, Bin Zou
  • Patent number: 7352558
    Abstract: An inexpensive and reliable dry process based capacitor and method for making a self-supporting dry electrode film for use therein is disclosed. Also disclosed is an exemplary process for manufacturing an electrode for use in an energy storage device product, the process comprising: supplying dry carbon particles; supplying dry binder; dry mixing the dry carbon particles and dry binder; and dry fibrillizing the dry binder to create a matrix within which to support the dry carbon particles as dry material.
    Type: Grant
    Filed: April 2, 2004
    Date of Patent: April 1, 2008
    Assignee: Maxwell Technologies, Inc.
    Inventors: Linda Zhong, Xiaomei Xi, Porter Mitchell, Bin Zou
  • Patent number: 7342770
    Abstract: A dry process based capacitor and method for using one or more recyclable electrode film structure is disclosed.
    Type: Grant
    Filed: April 2, 2004
    Date of Patent: March 11, 2008
    Assignee: Maxwell Technologies, Inc.
    Inventors: Porter Mitchell, Linda Zhong, Xiaomei Xi
  • Publication number: 20080016664
    Abstract: Electrodes of a double-layer capacitor are designed so that sub-capacitors formed at each electrode are stressed substantially equally at the rated voltage of the double-layer capacitor. In an exemplary embodiment, each electrode includes a current collector and an active electrode layer, such as a layer of activated carbon. The electrodes are held apart by a porous separator, and the assembly is immersed in an electrolyte. The thicknesses of the active electrode layers differ, resulting in asymmetrical construction of the capacitor. Different thicknesses cause the sub-capacitors to have different capacitances. When voltage is applied to the double-layer capacitor, the voltage is divided unequally between the unequal sub-capacitors. Properly selected thicknesses allow the voltages at the sub-capacitors to stress equally each sub-capacitor. The rated voltage of the double-layer capacitor can then be increased without overstressing the sub-capacitors.
    Type: Application
    Filed: May 22, 2007
    Publication date: January 24, 2008
    Applicant: MAXWELL TECHNOLOGIES, INC.
    Inventors: Porter Mitchell, Xiaomei Xi, Linda Zhong, Bin Zou
  • Patent number: 7295423
    Abstract: A dry process based capacitor and method for making a self-supporting dry adhesive electrode film for use therein is disclosed.
    Type: Grant
    Filed: April 2, 2004
    Date of Patent: November 13, 2007
    Assignee: Maxwell Technologies, Inc.
    Inventors: Porter Mitchell, Xiaomei Xi, Linda Zhong, Bin Zou
  • Publication number: 20070257394
    Abstract: In one embodiment, a feeder for agglomerating particles comprises an enclosure that has an inlet and an outlet and that is adapted to receive a predetermined amount of the agglomerating particles. An inlet valve controls entry into the enclosure, while an outlet valve controls discharge from the enclosure. A transportation system such as an auger system carries the agglomerating particles from the outlet valve to the inner portion of a drum, and, in order to prevent a clogging of the transportation system, the speed of the transportation system is coordinated with the opening rate of the outlet valve. The drum is adapted to spread out the agglomerating particles through perforations in the drum wall, so to cause the agglomerating particles to be delivered from the inner portion of the drum to a conveyor system outside the drum at a substantially uniform rate.
    Type: Application
    Filed: May 8, 2006
    Publication date: November 8, 2007
    Applicant: Maxwell Technologies, Inc.
    Inventors: James Borkenhagen, Porter Mitchell
  • Publication number: 20070242415
    Abstract: An energy storage device comprises a pair of electrodes in contact with an electrolyte and a dielectric separator therebetween. The separator comprises a chelating material capable of binding parasitic to ions with the electrolyte, so to prevent the free circulation of the parasitic ions within the electrolyte. In one embodiment, the chelating material comprises chitosan, which may be provided in fibrous form and which may be included within a non-woven fabric of cellulosic and/or olefinic, or which may be instead coated on the separator or otherwise comprised in the separator. In another embodiment, the chelating material comprises chitosan, and the ion-binding capability of the chitosan is enhanced by chemically binding a chelating agent to the chitosan so to create a multi-dentate ligand that binds with the parasitic ions, particularly multi-valent metal ions, to create coordination compounds. One such chelating agent is ethylendiamine tetraacetic acid (EDTA).
    Type: Application
    Filed: April 14, 2006
    Publication date: October 18, 2007
    Applicant: Maxwell Technologies, Inc.
    Inventor: Porter Mitchell
  • Publication number: 20070190424
    Abstract: A dry process based energy storage product and method for making is disclosed.
    Type: Application
    Filed: October 14, 2005
    Publication date: August 16, 2007
    Applicant: Maxwell Technologies, Inc.
    Inventors: Porter Mitchell, Linda Zhong, Xiaomei Xi, Bin Zou
  • Publication number: 20070146965
    Abstract: An ultracapacitor design minimizes the internal pressure of the cell package by using gas getters, either alone or in combination with a resealable vent in the package. Reducing pressure extends the life of the ultracapacitor. The primary gas types generated within a particular ultracapacitor are measured under multiple possible application conditions. Such conditions may include variables of temperature, application voltage, electrolyte type, length of use, and cycles of use. The primary gas components may be determined and suitable gas getters for different conditions may be formulated. The gas getters may be packed within the ultracapacitor packages, formulated as a negative electrode, doped into the negative current collector, or layered with the negative current collector.
    Type: Application
    Filed: November 22, 2006
    Publication date: June 28, 2007
    Inventors: Porter Mitchell, Robert Crawford, Xiaomei Xi, Linda Zhong
  • Publication number: 20070146966
    Abstract: Particles of active electrode material are made by blending or mixing a mixture of activated carbon, optional conductive carbon, and binder. In selected implementations, binder content in the electrode material is relatively low, typically the binder content of the mixture being between about 3 percent and about 10 percent by weight. The electrode material may be attached to a current collector to obtain an electrode for use in various electrical devices, including a double layer capacitor. The composition of the mixture increases the energy density and the integrity of the electrode.
    Type: Application
    Filed: November 22, 2006
    Publication date: June 28, 2007
    Inventors: Linda Zhong, Xiaomei Xi, Porter Mitchell
  • Patent number: 7227737
    Abstract: Electrodes of a double-layer capacitor are designed so that sub-capacitors formed at each electrode are stressed substantially equally at the rated voltage of the double-layer capacitor. In an exemplary embodiment, each electrode includes a current collector and an active electrode layer, such as a layer of activated carbon. The electrodes are held apart by a porous separator, and the assembly is immersed in an electrolyte. The thicknesses of the active electrode layers differ, resulting in asymmetrical construction of the capacitor. Different thicknesses cause the sub-capacitors to have different capacitances. When voltage is applied to the double-layer capacitor, the voltage is divided unequally between the unequal sub-capacitors. Properly selected thicknesses allow the voltages at the sub-capacitors to stress equally each sub-capacitor. The rated voltage of the double-layer capacitor can then be increased without overstressing the sub-capacitors.
    Type: Grant
    Filed: October 27, 2004
    Date of Patent: June 5, 2007
    Assignee: Maxwell Technologies, Inc.
    Inventors: Porter Mitchell, Xiaomei Xi, Linda Zhong, Bin Zou
  • Publication number: 20070122698
    Abstract: Dry process based energy storage device structures and methods for using a dry adhesive therein are disclosed.
    Type: Application
    Filed: October 14, 2005
    Publication date: May 31, 2007
    Applicant: Maxwell Technologies, Inc.
    Inventors: Porter Mitchell, Xiaomei Xi, Linda Zhong, Bin Zou
  • Publication number: 20070026317
    Abstract: Composite electrodes are constructed with pressure-bonding techniques instead of an adhesive. A current collector is made from aluminum foil roughed on both surfaces. The surfaces of the collector can be treated to enhance adhesion to the surfaces. Layers of film that includes active electrode material, such as activated carbon, are fabricated and pressure-bonded to the current collector using a calender with heated rollers. The resulting composite sheet is then processed to shape electrodes, which can be used in electrical energy storage devices, including double layer capacitors.
    Type: Application
    Filed: July 17, 2006
    Publication date: February 1, 2007
    Inventors: Porter Mitchell, Xiaomei Xi, Linda Zhong
  • Publication number: 20060246343
    Abstract: A dry particle packaging system and method for making is disclosed.
    Type: Application
    Filed: October 14, 2005
    Publication date: November 2, 2006
    Applicant: Maxwell Technologies, Inc.
    Inventors: Porter Mitchell, Xiaomei Xi, Bin Zou, Linda Zhong
  • Patent number: 7102877
    Abstract: A method for making an electrode including a particle based film is disclosed in which the film is coated and/or impregnated with veins of conductive material. A support backing is placed adjacent to one side of the film to provide support and prevent damaging the film while the conductive material is applied onto the opposite side of the film. The film is bonded directly to a current collector of an energy storage device.
    Type: Grant
    Filed: July 28, 2004
    Date of Patent: September 5, 2006
    Assignee: Maxwell Technologies, Inc.
    Inventors: Porter Mitchell, Xiaomei Xi, Linda Zhong, Vincent Hermann
  • Patent number: 7090946
    Abstract: Composite electrodes are constructed with pressure-bonding techniques instead of an adhesive. A current collector is made from aluminum foil roughed on both surfaces. The surfaces of the collector can be treated to enhance adhesion to the surfaces. Layers of film that includes active electrode material, such as activated carbon, are fabricated and pressure-bonded to the current collector using a calender with heated rollers. The resulting composite sheet is then processed to shape electrodes, which can be used in electrical energy storage devices, including double layer capacitors.
    Type: Grant
    Filed: August 12, 2004
    Date of Patent: August 15, 2006
    Assignee: Maxwell Technologies, Inc.
    Inventors: Porter Mitchell, Xiaomei Xi, Linda Zhong