Initial-Stage Performance Evolution of Solid Oxide Fuel Cells Based on Polarization Analysis
Yige Wang, Zewei Lyu, Minfang Han, Zaihong Sun, Kaihua Sun
Abstract
The performance evolution of solid oxide fuel cells (SOFCs) is more pronounced and non-linear in the initial stage, determining the output level during subsequent long-term operation. In this study, an industrial-size (10×10 cm 2 ) cell was tested under 0.1 A cm -2 for 96 hours. I-V-P curves and EIS data under different DC bias (0, 0.05, 0.10, 0.30, 0.50, 0.70 A cm -2 ) were periodically recorded every 24 hours to investigate the mechanism of initial-stage performance evolution. The ohmic loss was identified as the main contributor to the total overpotential, especially under large current density. The cell performance increased during 4-24 h due to the enhancement of anode gas-phase diffusion/conversion processes, while the performance degraded significantly during 48-96 h caused by the deterioration of anode charge transfer reaction. The EIS evolution trend under different DC bias was consistent, while the evolution degree was larger under smaller current density.