EEStor, Inc., the publicly taciturn developer of a promised high-power-density ceramic ultracapacitor (the Energy Storage Unit—EESU), says that it has met critical certified production milestones for the EESU component materials in three areas: particle crystallization, purity, and size. The company said that it expected that meeting these certified materials production milestones will help it meet present and future energy storage goals, as well as production consistency.
According to the company’s initial patent, the EESU is based on high-permittivity CMBT (composition-modified barium titanate) ceramic powder. This powder is double coated with the first coating being aluminum oxide and the second coating calcium magnesium aluminosilicate glass.
The EESU alternates multilayers of nickel electrodes and the high-permittivity powder. The resulting parallel configuration of components has the capability to store electrical energy in the range of 52 kWh, according to the document, with weight for a unit of that capacity in the range of 336 pounds (152 kg).
According to EEStor, the EESU will not degrade due to being fully discharged or recharged, and also can be rapidly charged without damaging the material or reducing its life. The cycle time to fully charge a 52 kWh EESU would be in the range of 4 to 6 minutes with sufficient cooling of the power cables and connections.
Edward D. Golla, PhD, Laboratory Director for Texas Research International (acting as an independent agent) certified that EEStor’s test equipment, procedures, and techniques are capable of providing the required testing accuracy for chemicals and powder production processing analyses reflected in the announcement.
Particle Crystallization. EEStor, Inc. has certified the completeness of the powder crystallization of the constituents utilized in producing its CMBT powders—one of its most critical technical milestones. The percent of the constituents crystallized in the CMBT powders ranged from 99.57% to 100.00% with the average being 99.92%. EEStor said that this level of crystallization “provides the path for the possibility” of providing the published energy storage for present products and major advancements in energy storage for future products.
Purity. The purification of the EEStor, Inc. chemicals has been certified by Southwest Research Institute, Inc. (SwRI)—the same chemical analysis company as referenced in EEStor’s press release dated January 17, 2007 (earlier post) which announced two earlier production milestones.
EEStor has now improved its chemical purity to the parts-per-billion range. The aluminum oxide particle coating material purification has been certified to be in the parts-per-trillion level. Achieving these levels of purification are additional major factors in allowing EEStor, Inc. the potential to reach its target working voltage.
EEStor has certification data from outside sources that purified aluminum oxide, in the range that it has certified, can have a voltage breakdown of 1,100 volts per micron. The target working voltage of EEStor’s chemical processes is at 350 volts per micron. This provides the potential for excellent protection from voltage breakdown.
Size. Ian Treviranus of HORIBA Instruments Inc., using that company’s LA-950 particle measurement system, certified that EEStor has achieved their goal of producing powder particles in the range of 1 micron with a very narrow particle size distribution.
EEStor has certification data that indicates achieving powder particle of this size and distribution along with the aluminum oxide particle coating assists the company in meeting the energy storage stabilization over the temperature range of interest for key applications.
Polarization. In its announcement, EEstor also noted that its a flexible matrix concept described in its patents could provide the potential of multiple technical and production advantages. One of the technical advantages indicated is assisting in providing polarization of the ultra capacitors. Polarization along with other proprietary processing steps provides the potential of a polarization saturation voltage the company requires to meet its targets.
(A hat-tip to Marcus!)
US Patent 7,033,406: Electrical-energy-storage unit (EESU) utilizing ceramic and integrated-circuit technologies for replacement of electrochemical batteries (April 25, 2006)