Thermal Analysis of a Microtubular Solid Oxide Fuel CellUsing Electrochemical Impedance Spectroscopy

摘要

A thermal analysis of the anode, cathode and electrolyte of apractical solid oxide fuel cell (SOFC) is performed. Electrochemicalimpedance spectroscopy with two-electrode set-up is employed onan anode-supported microtubular SOFC. This cell is an intermediatetemperature SOFC composed of a Ni/(ZrO_2)_(0.9)(Y_2O_3)_(0.1) cermet anode,a La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.2)O_(2.8) electrolyte, and an (La_(0.6)Sr_(0.4))(Co_(0.2)Fe_(0.8))O_3cathode. A common equivalent circuit is applied to impedancespectra to acquire the resistances at the anode and cathode, and thecell Ohmic resistance. By numerically integrating these resistances,overpotentials are evaluated. The overpotentials and entropybalances, i.e., the single electrode Peltier heats, at the anode andcathode give individual heat production rates. By analyticallyintegrating energy balance equations incorporating the heatproduction rates, temperatures at the anode and cathode surfaces areobtained and agree well with those measured with thermocouples.