University of Oregon scientists who analyzed the material, which was synthesized by a research group at the Massachusetts Institute of Technology, say they have discovered that electrical charges flow through it in an unexpected but potentially advantageous way. The material acts as metal in one direction and a semiconductor in other directions - properties that allow the electrical charges to flow between atoms.
Such materials, say the researchers, could eventually lead to new supercapacitor and battery technology for fast and precise pulsed power.
"This is an important result, because it means that charges are flowing through material in a direction where things are not technically touching," says Christopher Hendon, a professor in the UO’s Department of Chemistry and Biochemistry and member of the Materials Science Institute. "As a design principle, doing that is something we've been working on a long time."
The research builds on efforts that began 20 years ago by numerous labs to produce electrically conductive metal organic frameworks - sponge-like material with extremely high surface areas. "We've taken a type of material that we have conventionally thought of as simply a sponge and demonstrated that you can conduct electricity through it in different directions," says Hendon. "As a result, these types of materials now have broadened their applications to energy storage devices."
A challenge in making such conductive metal organic frameworks, says Hendon, is that charges traditionally are expected to flow in the direction of the points of connectivity.
"In this case, however, we noticed that the material was conducting and suspected that the current was flowing in the non-connected direction," he says. "Our theory led us to find that the conductivity was flowing perpendicular to the connectivity."
That means, say the scientists, that conductivity can be driven by how stacked two-dimensional sheets are fitted above and below the new spongy organic-lanthanide material. This could lead to devices that rapidly charge and discharge