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
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
Abstract: A long life double layer capacitor and method of making the same including a case and a first terminal with an electrically insulating hermitic seal interposed between the first terminal and the case. A first current collector foil is electrically coupled to an interior portion of the first terminal and a first electrode comprising carbon which is juxtaposed against the first current collector foil. A porous separator is then juxtaposed against the first electrode comprising carbon and separating the first electrode from a second electrode comprising carbon. A second current collector foil is juxtaposed against a side of the second electrode and is electrically coupled to the second terminal.
Type:
Grant
Filed:
March 31, 2004
Date of Patent:
August 15, 2006
Assignee:
Maxwell Technologies, Inc.
Inventors:
C. Joseph Farahmandi, John M. Dispennette, Edward Blank, Robert W. Crawford, Chenniah Nanjundiah
Abstract: Electrodes are constructed with pressure-bonding techniques that simplify alignment of various electrode components during lamination. In an exemplary embodiment, a current collector is made from aluminum foil that has been roughed or pitted on both surfaces. The surfaces of the current collector can be further treated to enhance adhesion properties of these surfaces. Layers of film that include active electrode material, such as activated carbon particles, are fabricated using non-lubricated techniques. Each film is coated on one side with an adhesive binder solution, such as a thermoplastic solution. The adhesive binder is dried, and the films are laminated to the current collector using a calender with heated rollers. The resulting electrode product is processed to shape electrodes, which can then be used in electrical energy storage devices, including double layer capacitors.
Type:
Application
Filed:
July 28, 2004
Publication date:
July 6, 2006
Applicant:
Maxwell Technologies, Inc.
Inventors:
Porter Mitchell, Xiaomei Xi, Linda Zhong
Abstract: A coated electrode is provided for use in energy storage devices. The coated electrode comprises a dry fibrillized polymer that is fibrillized with no processing additives.
Type:
Application
Filed:
April 2, 2004
Publication date:
July 6, 2006
Applicant:
Maxwell Technologies, Inc
Inventors:
Linda Zhong, Porter Mitchell, Vincent Hermann, Chenniah Nanjundiah
Abstract: A plurality of high capacitance capacitors are coupled to supply or accept large currents. Bus bars are welded to the capacitors to provide improved thermal performance as well as self-supporting rigidity to the geometrical structure formed by the capacitors and the bus bars.
Abstract: A method and a system for the detection and correction of errors in memory systems is disclosed. In one embodiment, a method of error detection in a memory system having a plurality (m>1) of memory devices includes generating check bits for each of a plurality of data sets, dividing each memory device into a plurality (n>1) of segments. The plurality of data sets are interleaved to form a plurality (p>1) of words. Each word includes at least one segment from two or more of the memory devices. Detection and correction may utilize one or more parallel Reed-Solomon decoder and encoder. The system and method allow for the efficient detection and/or correction of memory device errors and bit errors in one or more memory devices.
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:
Application
Filed:
July 28, 2004
Publication date:
July 6, 2006
Applicant:
Maxwell Technologies, Inc.
Inventors:
Porter Mitchell, Xiaomei Xi, Linda Zhong
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 in 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:
April 2, 2004
Publication date:
June 22, 2006
Applicant:
Maxwell Technologies, Inc.
Inventors:
Linda Zhong, Xiaomei Xi, Porter Mitchell, Bin Zou
Abstract: A high voltage capacitor design is provided that provides improved performance. The high voltage capacitor includes a stack of mechanically joined capacitor cells, which in one variant utilize a separator formed of two layers of paper. In one version, the high voltage capacitor may be used as a capacitative voltage divider.
Abstract: High capacitance capacitors are provided to supply or accept large currents. As current flow through a capacitor increases, heat may be generated. Above a certain threshold temperature or current, a capacitor may fail. The present invention addresses capacitor's tendency to fail at higher currents and/or higher temperatures.
Abstract: High capacitance capacitors are provided to supply or accept large currents. As current flow through a capacitor increases, heat may be generated. Above a certain threshold temperature or current, a capacitor may fail. The present invention addresses capacitor's tendency to fail at higher currents and/or higher temperatures.
Abstract: Particles of active electrode material, such as a fibrillized mixture of carbon, and binder are deposited onto a surface of a current collector sheet. The current collector sheet and the particles are processed in a high-pressure nip, such as a calender. As a result of the high-pressure processing, a film of active electrode material is formed on and bonded to the surface of the current collector sheet. The process is then repeated to form a second film on the second surface of the current collector sheet. In an embodiment, the particles are applied to both surfaces of the current collector sheet at the same time, followed by a pass through a calender. The current collector sheet with the bonded films is shaped into electrodes suitable for use in various electrical devices, including double layer capacitors.