loading page

Tuning defect nonequilibrium of brownmillerite Sr1+xY2-xO4+δ for rich-oxygen-vacancy direct ammonia SOFC cathode
  • +6
  • Fulan Zhong,
  • Yan Zhang,
  • Yu Luo,
  • Chongqi Chen,
  • Huihuang Fang,
  • Chen Zhou,
  • Li Lin,
  • Chak-tong Au,
  • Lilong Jiang
Fulan Zhong
Author Profile
Yu Luo
Fuzhou University
Author Profile
Chongqi Chen
Author Profile
Huihuang Fang
Author Profile
Chak-tong Au
National Engineering Research Center of Chemical Fertilizer Catalyst
Author Profile
Lilong Jiang
Fuzhou University

Corresponding Author:jll@fzu.edu.cn

Author Profile

Abstract

In this study, we prepared SrR2O4+δ (SRO, R=Y, Yb, Gd, Sm) of brownmillerite structure. Among the four n-type SRO semiconductors, SYO is the most negative in conduction band and the smallest in band gap. As a result, the SYO-based SOFC can offer a maximum power density (MPD) of 1.03W/cm-2 at 800°C, which is higher than that based on the other three SRO oxides. The introduction of larger Sr2+ at the B sites of Sr1+xY2-xO4+δ [SYO(x)] causes decrease of band gap, resulting in a 4-fold increase of electronic conductivity. The foreign Sr2+ creates surface oxygen vacancies to boost interfacial transport. The measurement of oxygen transport reveals that SYO(0.10) exhibits a bulk diffusion coefficient 500 folds higher than that of LSM. An anode supported Ni-YSZ|YSZ|SYO(0.10)-60YSZ DA-SOFC yields an MPD of 0.24W/cm2 at 600°C and 1.21 W/cm2 at 800°C with remarkable stability, about 1.73- and 1.29-folds higher than that of LSM-based SOFC, respectively.