  Design novel solid oxide electrolyte with enhanced ionic conductivity forms
one of the Holy Grails in the field of materials science due to its great
potential for wide range of energy applications. Conventional solid oxide
electrolyte typically requires elevated temperature to activate the ionic
transportation, while it has been increasing research interests to reduce the
operating temperature due to the associated scientific and technological
importance. Here, we report a conceptually new solid oxide electrolyte,
HSrCoO2.5, which shows an exceptional enhanced proton conductivity at low
temperature region (from room temperature to 140 oC). Combining both the
experimental results and corresponding first-principles calculations, we
attribute these intriguing properties to the extremely-high proton
concentration as well as the well-ordered oxygen vacancy channels inherited
from the novel crystalline structure of HSrCoO2.5. This result provides a new
strategy to design novel solid oxide electrolyte with excellent proton
conductivity for wide ranges of energy-related applications.
