2-Dimensional Ion Conducting Bismuth Vanadates for Electrochemical Devices

• Applicant: Professor Dr.-Ing. Ralf Moos
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2012 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 198685931

The scientific goal of this collaborative project is to develop a defect chemistry model and determine fundamental thermal/conduction/transport (tensor) properties for acceptor doped bismuth vanadate ceramic (BIMEVOX), a family of non-standard, bi-dimensional fast ion conductors. This involves a comprehensive synthesis, characterization, and testing plan, with key objectives: 1. Achieve the highest possible (near theoretical density) BIMEVOX ceramics via hot forging2. Achieve high crystallographic orientation in BIMEVOX ceramics via hot forging (bulk samples) and tape casting (thick films). 3. Characterize the (anisotropic) thermal conductivity and thermal expansion.4. Measure the (anisotropic) transport properties of BIMEVOX by impedance spectroscopy, polarization, and thermoelectric measurements as a function of temperature and pO2 5. Create defect chemical models (Kroger Vink), with verification from above measurements. A broad impact goal is the use of bulk and thick film BIMEVOX in electrochemical devices for operation in a temperature regime considered unusually low for ionic conductors (350°C to 500°C). BIMEVOX will be incorporated into novel devices such as direct thermoelectric and mixed potential gas sensors, de-NOx cells and single chamber fuel cells.

• DFG Programme: Research Grants