Apr 5 2012
Dais Analytic Corporation announced today the Company’s development progress, since its last report in September 2011, on its program to produce a capacitive energy storage material set for use as an ultracapacitor named “NanoCap™”.
The Company, working with the University of Florida (UF), tested different capacitive dielectric structures created by Dais from its family of Aqualyte™ high charge density polyelectrolyte materials. Critical to the materials performance as a capacitive dielectric are internal resistance, breakdown voltage, dielectric loss and relative permittivity.
Relative permittivity (also called the dielectric constant) is important because the larger the relative permittivity the more electrical energy per unit of volume can be stored when exposed to an electric field. As shown in Figure 1, highlighting the University of Florida’s test data, Dais’ Aqualyte materials dielectric constant is large, making it suitable for high energy density capacitive structures.
Making a comparison, Denise Sanderson, Dais’ Managing Director of Business Development said, “This is analogous to a computer hard drive. Today, a hard drive can hold a finite amount of data before you need to add more hard drives. By using the Aqualyte material set with its high dielectric constant demonstrated by the University of Florida, in a device of the type we project, NanoCap will provide more energy in a given space. It is like having the ability to place much more data in a standard hard drive making your hard drive more efficient.”
An ultracapacitor is a newer way of storing electric energy. Instead of storing energy electrochemically - like a D-Cell battery - an ultracapacitor stores energy in an electric field or, in Dais’ case in the Aqualyte material set.
Ultracapacitors have multiple advantages over conventional electrochemical batteries, including a potential estimated ten-fold increase in lifetime, resistant to changes in temperature, shock and overcharging, and discharging efficiency. Ultracapacitors require less maintenance than conventional batteries and are eco-friendly when disposed because they lack toxic chemicals. The benefit to an end-user extends beyond just using a more efficient power source. By being able to use higher voltages, electrical components in a product can be made more efficient as well (e.g., in an electric lawn mower it can use a smaller, more efficient motor which has superior grass cutting ability).
When completed, NanoCap is projected to power a broad range of energy consuming devices including most forms of transportation, energy storage for electric grid and renewable energy sources such as wind and solar power, telecommunications equipment, and others.
“The material continues to move toward meeting market driven performance metrics and we see the materials having capabilities beyond current testing levels,” states Scott Ehrenberg, Dais’ Chief Technology Officer. “With completion of the planned development program – including the material set and an architecture projected to take maximum advantage of our materials – we maintain Aqualyte will be able to deliver energy storage levels equal to, or greater than, existing electrochemical technologies while retaining capacitive characteristics.”
The Company, from the testing at UF, has demonstrated high relative permittivity as shown in the graph.
The Dais team continues to create and test capacitive structures exhibiting dielectric breakdown voltages in excess of 20,000 volts accompanied by internal direct current resistances of greater than 109 ohms per square and capacitive functionality with relative permittivities of greater than 104 resulting in hundreds of microfarads of capacitances per cm2 of plate area.
“Steady and improving performance is important. So is the price of the materials set for the intended applications. An integral part of NanoCap’s development is to deliver the material set at the needed performance levels for a price at or near existing energy storage alternatives,” said Sanderson. “At this time we project we are meeting the price and performance targets for the materials set and intended applications.”