CaltechTHESIS
  A Caltech Library Service

High-throughput Characterization of Solid Oxide Fuel Cell Cathode Materials

Citation

Kucharczyk, Christopher James (2018) High-throughput Characterization of Solid Oxide Fuel Cell Cathode Materials. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z094-9907. http://resolver.caltech.edu/CaltechTHESIS:05302018-201642452

Abstract

Solid oxide fuel cells are electrochemical devices which convert chemical energy directly to electricity. The extreme environments in which these devices operate require the use of expensive components to withstand degradation. To lower operating temperatures and therefore cost, materials discovery efforts have targeted new electrodes with high ionic and electronic conductivity, but these studies often convolute electrode morphology and performance, masking the inherent activity of electrode materials. In this work, a high-throughput experimental technique utilizing a robotic scanning impedance probe is applied to materials libraries to rigorously compare the performance of electrode materials and characterize fundamental electrode properties.

Two cathode materials libraries are studied in-depth: the perovskite material La1-xSrxCo1-yFeyO3-δ (LSCF) and the double perovskite material PrBa0.5Sr0.5Co2-xFexO5+δ (PBSCF). Each materials library is investigated through the entire regime of cobalt and iron doping and results are obtained on both oxide-ion- and proton-conducting electrolyte materials. For LSCF, a four-fold increase in electrochemical resistance is observed from the cobalt-dominant endmember LSC64 to the iron-dominant endmember LSF64 on an oxygen-ion conducting substrate, concurrent with a decrease in chemical capacitance indicating lower oxygen vacancy concentration. For PBSCF, proton conductivity is observed through the bulk of the film, leading to its use in a real proton-conducting ceramic fuel cell that demonstrates exceptional performance at low temperatures (> 500mW/cm2 at 500°C) while remaining stable over hundreds of hours of testing. These results demonstrate the power and robustness of this high-throughput approach in characterizing both well-known and novel materials, and show great promise for future targeted searches of high-performance materials.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Solid oxide fuel cells; fuel cells; cathodes; LSCF; LSC; LSF; PBSCF
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Materials Science
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Haile, Sossina M.
Thesis Committee:
  • Haile, Sossina M.
  • Atwater, Harry Albert (chair)
  • Johnson, William Lewis
  • Rossman, George Robert
Defense Date:7 March 2018
Non-Caltech Author Email:chris.kucharczyk (AT) gmail.com
Record Number:CaltechTHESIS:05302018-201642452
Persistent URL:http://resolver.caltech.edu/CaltechTHESIS:05302018-201642452
DOI:10.7907/Z094-9907
ORCID:
AuthorORCID
Kucharczyk, Christopher James0000-0002-4712-839X
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:10977
Collection:CaltechTHESIS
Deposited By: Christopher Kucharczyk
Deposited On:01 Jun 2018 23:27
Last Modified:08 Jun 2018 20:49

Thesis Files

[img]
Preview
PDF - Final Version
See Usage Policy.

7Mb

Repository Staff Only: item control page