In-situ characterization of temperature distributions in planar solid oxide fuel cells for various operation conditions

Solid oxide fuel cells (SOFCs) are greatly superior to various other power generation systems due to their high efficiencies, great multi-fuel flexibility, and inexpensive catalyst materials. However, SOFCs still have experienced significant performance degradation. The uneven distributions of temperature inside the SOFCs are the main factor leading to premature SOFC performance degradation and even failures. This study measured planar SOFC internal temperature distributions. The measurements were used to evaluate the effects of several critical parameters, including the current density, hydrogen flow rate, air flow rate, and gas preheat temperature on the temperature distribution and electrical output characteristics. The experimental findings demonstrate that the SOFC temperatures increase, the temperature differences increase, and the temperature distribution becomes more non-uniform with increasing current density. The SOFC temperatures decrease and the maximum temperature gradients decrease with increasing gas flow rate. SOFC temperature uniformity improves by 11.64 % with increasing H2 flow rate at a current density of 0.3 A/cm2. However, the air flow rate is the main factor affecting the SOFC temperature distributions. The cathode temperatures are higher than the anode temperatures. Higher gas preheat temperatures favor the SOFC operation. These measurements provide further insight into the influence of the various working conditions on the temperature non-uniformities within SOFC and provide insights into how to optimize SOFC designs and operational strategies.