Quantifying the Effect of Temperature and Humidity on Infiltrated Cell Performance Using Electrochemical Impedance Spectroscopy and Distribution of Relaxation Times Analysis

Abstract

Infiltrating nanoparticle electrocatalysts into solid oxide fuel cells (SOFCs) has been shown to improve their intermediate-temperature performance by increasing the density of reaction sites, known as triple phase boundaries (TPBs), in the electrode. By increasing TPB density with infiltration, anode activation polarization is mitigated and cell performance improves relative to an uninfiltrated cell, especially at low temperatures. In this study, electrochemical impedance spectroscopy and distribution of relaxation times analyses were performed on baseline and Ni-infiltrated NiYSZ anode symmetric cells. A transmission line model (TLM) was used to deconvolute the electrode processes. The effects of temperature and humidity on TLM parameters, and the relative polarization contributions of various charge transfer processes will be discussed.