Complex Dielectrics by Design

Reference number: STC-PS-0949
Inventor(s): C. Luhrs; J. Phillips
For more information, contact: Erin M. Beaumont (505-272-7912) or Lisa Kuuttila (505-272-7905)

Patent(s)

Application(s) pending

Background

As the world shifts from the current paradigm of energy storage and distribution, there is increasing interest in significantly enhancing a number of old energy storage technologies such as batteries and super-capacitors. It is widely conceded that batteries have better “energy density”, but it is the rapid charge/discharge cycle and the stability over many, many cycles that make super-capacitors attractive for many possible applications.

This invention addresses the need of improving the capacity per weight/volume of a capacitor. The performance is enhanced through combining improved materials with a typical, straightforward design: high voltage, but low surface area.

Technology

In some sense, “dielectric constant” is a measure of how well an insulation material reduces the electric field within itself. Hence, an insulation material with the highest possible “field exclusion” would be the best dielectric. On this basis, an entirely new class of dielectrics has recently been developed. The new dielectric material consists of metal core particles with a coat of ceramic. Each component of this multi-material dielectric plays an important role and the combined properties of the three materials: matrix (e.g. Barium titinate) outer coat (e.g. alumina) and core (e.g. aluminum) are dramatically better than anything found in a single material. In particular, the metal component can have nearly infinite field exclusion which is far better than even the best materials currently employed, such as barium titanate (BaTiO3). The ceramic coat on the proposed bi-layer nanoscale metal particles would provide electric insulation allowing high packing density of the metal core particles without the short-circuit phenomenon heretofore always observed above 27% loading due to percolation. Literature data shows net capacitance increases nearly exponentially with metal loading. Hence the best enhancement observed to date, 8X (~25% loading) extrapolates to 100 X at 60 % loading. Only with the technology developed herein is the 60% loading limit possible.

Applications/Advantages

•Dramatic improvement in energy density, with a goal of a factor 100 X over existing electrostatic capacitors. Could lead to replacement of batteries with capacitors in many applications.
•No out of phase impedance even at very high frequency.
•Applicable to high frequency electronics
•Extreme flexibility-almost any metal can be used in conjunction with almost any ceramic

Keywords

Electronics, Energy

Related Categories

• Lithography, Semiconductor Fabrications, and Electronic Materials