Evaluation Method of Current Distribution in SOFC in Operation

Abstract

A method was developed to estimate local current in an SOFC. Lateral potential profile on a current collector plane was measured using multiple probes, and the local current was estimated as the second derivative of the potential. This concept was successfully demonstrated by experiments measuring 1-dimensional current distribution on a small tubular cell. The condition for the measurement was optimized according to the ratio of resistance on the interconnect to that through the cell. The same concept was applied to a planar single cell flowing current diagonally on the top and bottom plates. Numerical estimation revealed that the 2-dimensional current distribution can be roughly estimated from the measurement of potential on the edges of the interconnect plates. Furthermore, the potential on the current collector was found to be a good indicator of internal current in a cell upon transient operations.