Abstract: Films of active electrode material, such as films made from carbon and fibrillized polymer, are attached to a porous separator. Outer surfaces of the films (i.e., surfaces opposite those adjoining the separator) are then covered with current collectors. The 5 resulting stack is usable in fabrication of electrical energy storage devices. The stack can be shaped as needed, connected to terminals, and immersed in an electrolytic solution to provide a double layer capacitor.
Type:
Grant
Filed:
August 2, 2009
Date of Patent:
April 5, 2011
Assignee:
Maxwell Technologies, Inc.
Inventors:
Porter Mitchell, Xiaomei Xi, Linda Zhong
Abstract: Electronic circuits couple energy storage devices, such as double layer capacitors or rechargeable battery cells, to a power supply output, thereby improving noise suppression and extending ride-through capability of the power supply. In a typical circuit, an energy storage device is coupled in series with a switch that controls the charging current into the energy storage device. The switch is controlled by a comparator that receives a signal related to the voltage level of the power supply. In some embodiments, the comparator also receives a feedback signal related to a charging current flowing into the energy storage device. The circuit is configured so that the switch limits the charging current to a predetermined current level, or does not allow the charging current to flow until the output voltage of the power supply reaches a predetermined voltage level.
Abstract: The fault-tolerant or self-correcting computer system is disclosed. The computer system that is provided with various sets of protections against failures that may be caused by space radiation, for example. Improved reliability of the system is achieved by scrubbing of the components on a regular schedule, rather than waiting for an error to be detected. Thus, errors that may go undetected for an extended period are not allowed to propagate and further damage the system. Three or more processors are provided to operate in parallel, and a controller is provided to receive signals from the processors and, using a voting logic, determines a majority signal value. In this manner, the controller can detect an error when a signal from one of the processors differs from the majority signal. The system is also provided with a scrubbing module for resynchronizing the processors after a predetermined milestone has been reached.
Abstract: A deformable and compressible active electrode dry film is manufactured from dry mixed dry active electrode material and dry binder powder. The electrode film and a current collector with a first surface may be stacked such that the first surface of the current collector is in contact with the dry film. The active electrode dry film and current collector may then be processed in a laminating device, such as a calendar. Lamination both densifies the active electrode film and bonds the film to the current collector.
Type:
Grant
Filed:
June 10, 2008
Date of Patent:
February 8, 2011
Assignee:
Maxwell Technologies, Inc.
Inventors:
Porter Mitchell, Xiaomei Xi, Linda Zhong
Abstract: Electronic circuits couple energy storage devices, such as double layer capacitors or rechargeable battery cells, to a power supply output, thereby improving noise suppression and extending ride-through capability of the power supply. In a typical circuit, an energy storage device is coupled in series with a switch that controls the charging current into the energy storage device. The switch is controlled by a comparator that receives a signal related to the voltage level of the power supply. In some embodiments, the comparator also receives a feedback signal related to a charging current flowing into the energy storage device. The circuit is configured so that the switch limits the charging current to a predetermined current level, or does not allow the charging current to flow until the output voltage of the power supply reaches a predetermined voltage level.
Abstract: A thermally fitted interconnect couples energy storage cells without the use of additional materials of fasteners. Variations of the interconnect can be used to facilitate fitting of multiple energy storage cell with multiple cell to cell spacings in a rapid and inexpensive manner.
Type:
Grant
Filed:
March 6, 2008
Date of Patent:
December 28, 2010
Assignee:
Maxwell Technologies, Inc.
Inventors:
Guy C. Thrap, James L. Borkenhagen, Mark Wardas, Adrian Schneuwly, Philippe Lauper
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:
Grant
Filed:
February 24, 2009
Date of Patent:
December 14, 2010
Assignee:
Maxwell Technologies, Inc.
Inventors:
Porter Mitchell, Xiaomei Xi, Linda Zhong, Bin Zou
Abstract: An active voltage management device and a method for actively managing a voltage level of an energy storage device are provided. The active voltage management device comprises: a pair of input terminals adapted to be connected to the energy storage device; a reverse polarity protection circuit coupled to the pair of input terminals; a voltage comparator circuit adapted to compare a second voltage associated with the voltage level of the energy storage device to a reference voltage and to provide an output based upon the comparison of the second voltage to the reference voltage; and a transistor adapted to operate in a linear mode to dissipate energy from the energy storage device at a substantially constant current level, wherein output of the voltage comparator circuit is adapted to activate the transistor when the second voltage is greater than or equal to the reference voltage.
Type:
Grant
Filed:
November 19, 2007
Date of Patent:
October 19, 2010
Assignee:
Maxwell Technologies, Inc.
Inventors:
Dragan Nebrigic, Jeffrey Johnstone, Vlastislav Haman, Hung Q. Ha
Abstract: Particles of active electrode material are made by blending mixing a mixture of activated carbon and binder. In selected implementations, sulfur level in the activated carbon is relatively low and the binder is inert. For example, sulfur content of the activated carbon and the resultant mixture is below 300 ppm and in other implementations, below 50 ppm. 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 electrode decreases current leakage of the capacitor.
Type:
Grant
Filed:
February 27, 2008
Date of Patent:
October 12, 2010
Assignee:
Maxwell Technologies, Inc.
Inventors:
Linda Zhong, Xiaomei Xi, Porter Mitchell
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:
Grant
Filed:
April 2, 2004
Date of Patent:
September 7, 2010
Assignee:
Maxwell Technologies, Inc.
Inventors:
Porter Mitchell, Linda Zhong, Vincent Hermann, Chenniah Nanjundiah
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:
January 31, 2008
Date of Patent:
September 7, 2010
Assignee:
Maxwell Technologies, Inc.
Inventors:
Linda Zhong, Xiaomei Xi, Porter Mitchell, Bin Zou
Abstract: A high reliability radiation shielding integrated circuit apparatus comprising a plurality of package layers; a radiation shielding lid or base coupled to the plurality of package layers; wherein the circuit die are shielded from receiving an amount of radiation greater than the total dose of tolerance of the circuit die. In one embodiment, an integrated circuit apparatus for use in high reliability applications is disclosed. The integrated circuit apparatus is designed to be highly reliable and protect integrated circuit die from failing or becoming unreliable due to radiation, mechanical forces, thermal exposure, or chemical contaminates.
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:
July 17, 2006
Date of Patent:
May 25, 2010
Assignee:
Maxwell Technologies, Inc.
Inventors:
Xiaomei Xi, Linda Zhong, Porter Mitchell
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:
November 17, 2009
Publication date:
May 13, 2010
Applicant:
MAXWELL TECHNOLOGIES, INC.
Inventors:
Linda Zhong, Porter Mitchell, Vincent Hermann, Chenniah Nanjundiah
Abstract: An energy storage device electrode product is provided. The product comprises: at least one current collector and at least one electrode film disposed adjacent to the at least one current collector. The at least one current collector comprises a plurality of voids extending through a thickness of the current collector, wherein the plurality of voids allow electrolyte to flow through the thickness of the current collector. The plurality of voids extending through the current collector is formed without reducing a surface area of a conductive material of the current collector disposed adjacent to the electrode by more than about fifty percent. A method of producing an electrode product and a double layer capacitor product are also disclosed.
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, iron level in the activated carbon is relatively low, a small amount of conductive carbon with low impurity levels and high conductivity is used, and the binder is inert. For one example, iron content of the activated carbon and the resultant mixture is below 20 ppm. 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 electrode decreases current leakage of the capacitor.
Type:
Application
Filed:
February 27, 2008
Publication date:
May 6, 2010
Applicant:
MAXWELL TECHNOLOGIES, INC.
Inventors:
Linda Zhong, Xiaomei Xi, Porter Mitchell
Abstract: Particles of active electrode material are made by blending mixing a mixture of activated carbon and binder. In selected implementations, sulfur level in the activated carbon is relatively low and the binder is inert. For example, sulfur content of the activated carbon and the resultant mixture is below 300 ppm and in other implementations, below 50 ppm. 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 electrode decreases current leakage of the capacitor.
Type:
Application
Filed:
February 27, 2008
Publication date:
April 22, 2010
Applicant:
MAXWELL TECHNOLOGIES, INC.
Inventors:
Linda Zhong, Xiaomei Xi, Porter Mitchell
Abstract: A high reliability radiation shielding integrated circuit apparatus comprising a plurality of package layers; a radiation shielding lid or base coupled to the plurality of package layers; wherein the circuit die are shielded from receiving an amount of radiation greater than the total dose of tolerance of the circuit die. In one embodiment, an integrated circuit apparatus for use in high reliability applications is disclosed. The integrated circuit apparatus is designed to be highly reliable and protect integrated circuit die from failing or becoming unreliable due to radiation, mechanical forces, thermal exposure, or chemical contaminates.
Abstract: An energy storage apparatus and article of manufacture is disclosed. In one embodiment, the energy storage apparatus comprises a jelly roll, having a first and second sheet and a first and second separator member, and at least one terminal element. In another embodiment, an article of manufacture comprising forming a cylindrical housing and stamping a longitudinal indentation on an exterior surface of the cylindrical housing is disclosed. In one alternate embodiment, the longitudinal indentation is adapted to slowly fracture under pressure exerted on an interior surface of the cylindrical housing, thereby preventing catastrophic failure, such as for example an explosion.