EFFECT OF STRUCTURE AND IMPURITIES ON CHARGE TRANSFER REACTIONS IN SOLID STATE ELECTROCHEMICAL DEVICES
EMSL Project ID
30429
Abstract
Interfaces between solid state electrodes, electrolytes, and the gas phase play an important role in the functioning of many solid state electrolyte devices. In actual devices, porous electrodes are employed both as the mechanical support and as a means to increase the geometrical dimensions over which electrochemical reactions actually occur. However, porous electrodes are unsuitable to obtain specific electrode kinetics information in a systematic way because of the inherent conflation of the effect of geometry and microstructure and the specific electrode kinetics. To circumvent this conflation, we propose to employ patterned electrode structures and heteroepitaxial thin films of electrode materials on single crystal solid electrolytes to investigate specific electrode kinetics and impurity effects on the stability of solid state electrochemical devices. To this end, we propose to use the unique materials deposition and characterization facilities available at EMSL. Thus, the goals of the proposed work are to obtain quantitative information on cathode electrode kinetics as a function of temperature, oxygen partial pressure, and impurities such as Cr, using phenomenological models that relate electrode geometry and specific reaction kinetics to the overall measured rates of the charge-transfer reactions. The quantitative information so obtained will help to distinguish between the relative importance of electrode pore surface areas and TPBs in the charge transfer process. Other important goals are to understand the structural rearrangements (vacancy formation and ordering, surface segregation, surface reconstruction, etc) that affect the oxygen reduction process at the two phase and the three phase interfaces.Project Details
Project type
Large-Scale EMSL Research
Start Date
2008-08-22
End Date
2009-08-23
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members