Electron-Phonon Renormalization in the Proton-Conducting Electrolyte BaZrO_{3} and Its Implications for High-Temperature Electrolysis

Electrical leakage is an inherent problem in solid-oxide fuel and electrolyzer cells, limiting their energy-conversion efficiency. High concentrations of electrons or holes can exacerbate this issue. However, it is largely unclear how the typical high operating temperatures of the systems influence...

Full description

Saved in:
Bibliographic Details
Main Authors: Shenli Zhang, Andrew J.E. Rowberg, Tadashi Ogitsu, Tuan Anh Pham, Joel B. Varley
Format: Article
Language:English
Published: American Physical Society 2025-03-01
Series:PRX Energy
Online Access:http://doi.org/10.1103/PRXEnergy.4.013013
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Electrical leakage is an inherent problem in solid-oxide fuel and electrolyzer cells, limiting their energy-conversion efficiency. High concentrations of electrons or holes can exacerbate this issue. However, it is largely unclear how the typical high operating temperatures of the systems influence their charge-carrier concentrations. In this work, we use first-principles calculations to examine how lattice vibrations impact electrical conductivity in conventional electrolytes, using BaZrO_{3} as a representative material. Our analysis shows that phonon-induced shifts in the band gap and band edges lead to a dramatic increase in p-type carrier concentrations at temperatures above 600 K, compared to models that neglect temperature effects. Additionally, we reveal the importance of oxygen-ion motion on band-edge positions, which makes valence-band-edge shift dominate the band-gap change. Our study provides a protocol for calculating phonon-induced changes in similar oxides, paving the way for interrogating electrical leakage in electrolytes for high-temperature operation.
ISSN:2768-5608