Orienting oxygen defects for enhanced oxygen reduction kinetics
November 20, 2013 — Functional oxygen defects are shown to result in a two orders of magnitude improvement of the catalytic oxygen reduction kinetics in epitaxial SrCoO2.5 films. This discovery will impact our understanding of the fundamental properties in multivalent transition metal oxides and provides technological insights into developing new strategies for advanced energy materials and systems.
Local structures ‒ key to improved gas adsorption in carbon materials
September 23, 2013 — Combined results from electron microscopy, neutron scattering, and theory, illustrate the link between local structures and adsorption properties in carbon materials.
Epitaxial oxygen sponges as low temperature catalysts
September 10, 2013 — Fast and reversible redox reactions at considerably reduced temperatures are achieved by epitaxial stabilization of multivalent transition metal oxides. This illustrates the unprecedented potential of complex oxides for oxide-ionics, where oxidation state changes are used for energy generation, storage and electrochemical sensing.
Fluid-like electrophoretic behavior observed in a solid crystal
September 03, 2013 — The position of coexisting mesoscale electronic phase domains in a complex oxide is shown to be controlled with electric fields in an electrophoretic process previously only observed in liquids. This discovery has important implications to our fundamental understanding of how electronic phase competition arises and persists while opening the door to new types of resistive switching possibilities.
Artificial SEI Enables High-Voltage Lithium-ion Batteries
September 03, 2013 — An artificial solid electrolyte interphase (SEI) of lithium phosphorus oxynitride (Lipon) enables the use of 5V cathode materials with conventional carbonate electrolytes in lithium-ion batteries.
Topotactic valence state control in epitaxial multivalent oxides
July 17, 2013 — Valence state control is demonstrated in a multivalent transition metal oxide (TMO) by topotactic transformation, i.e. the change of crystal structure via loss or gain of constituent elements.
Fundamental interactions of multiferroic BiFeO3
July 01, 2013 — The agreement between the measured and predicted terahertz (THz) excitations indicates that a microscopic model can provide the foundation for future work on BiFeO3, which is the only known room-temperature multiferroic. Due to the coupling between their electric and magnetic properties, mutliferroics would offer several advantages in magnetic storage devices and sensors.
Heavier D2 moves much faster than H2 at low temperatures
July 01, 2013 — Quantum confinement effects in carbon nanopores cause deuterium to diffuse as much as 76 times faster than the much lighter hydrogen at low temperatures. This surprising experimental result suggests that selectivity levels for separation of hydrogen isotopes unobtainable by other methods can be reached by using quantum properties of light molecules.
Superionic cathode enables high-energy lithium-sulfur batteries
June 10, 2013 — A family of new lithium polysulfidophosphate (LPSP) compounds is shown to enable stable cycling of all-solid-state lithium-sulfur (Li-S) batteries with long lifespans. Li-S batteries have a high theoretical energy density of 2600 Wh/kg, which is about 5 times higher than that of the state-of-the-art lithium-ion batteries.
Glass-like thermal transport in AgSbTe2: nano-scale insights to improve thermoelectric efficiency
May 16, 2013 — A spontaneously forming nanostructure is identified as the origin of the extremely low glass-like thermal conductivity of AgSbTe2.