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Title: Role of Exposure Atmospheres on Particle Coarsening and Phase Transformation of LiAlO 2

Abstract

The phase transformation and particle coarsening of lithium aluminate (α-LiAlO 2) in electrolyte are the major causes of degradation affecting the performance and the lifetime of the molten carbonate fuel cell (MCFC). The stability of LiAlO 2 has been studied in Li 2CO 3-Na 2CO 3 electrolyte under accelerated conditions in reducing and oxidizing gas atmospheres at temperatures of 650 and 750 for up to 500 hours. X-ray diffraction analyses show that the progressive transformation of α-LiAlO 2 to γ-LiAlO 2 phase proceeds with increasing temperature in lower P CO2 and lower P O2 environments. Spherical LiAlO 2 particles were transformed to coarsened pyramid-shape particles in 4% H 2-3% H 2O-N 2 and 100% N 2 (~10 ppm P O2 ) atmospheres. Under CO 2-rich atmospheres (4% H 2-30% CO 2-N 2 and 70% air-30% CO 2), both phase and particle size remained unchanged at 650 and 750ºC. The selected area electron diffraction (SAED) pattern analysis indicated that the large pyramidal shape particles (~30 μm) were γ-LiAlO 2 phase. Experimental observations and related simulation results pertaining to particle coarsening and phase transformation behavior of LiAlO 2 are presented.

Authors:
 [1];  [1];  [1];  [1];  [2];  [2];  [2];  [1]
  1. Univ. of Connecticut, Storrs, CT (United States). Center for Clean Energy Engineering and Dept. of Materials Science and Engineering
  2. FuelCell Energy, Inc., Danbury, CT (United States)
Publication Date:
Research Org.:
FuelCell Energy, Inc., Danbury, CT (United States); Univ. of Connecticut, Storrs, CT (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
1425155
Grant/Contract Number:
EE0006606
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of the Electrochemical Society
Additional Journal Information:
Journal Volume: 164; Journal Issue: 8; Journal ID: ISSN 0013-4651
Publisher:
The Electrochemical Society
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Lithium aluminate; Molten carbonate fuel cell; Particle coarsening; Phase transformation; Stability

Citation Formats

Heo, Su Jeong, Hu, Boxun, Uddin, Md Aman, Aphale, Ashish, Hilmi, Abdelkader, Yuh, Chao-Yi, Surendranath, Arun, and Singh, Prabhakar. Role of Exposure Atmospheres on Particle Coarsening and Phase Transformation of LiAlO 2. United States: N. p., 2017. Web. doi:10.1149/2.0181708jes.
Heo, Su Jeong, Hu, Boxun, Uddin, Md Aman, Aphale, Ashish, Hilmi, Abdelkader, Yuh, Chao-Yi, Surendranath, Arun, & Singh, Prabhakar. Role of Exposure Atmospheres on Particle Coarsening and Phase Transformation of LiAlO 2. United States. doi:10.1149/2.0181708jes.
Heo, Su Jeong, Hu, Boxun, Uddin, Md Aman, Aphale, Ashish, Hilmi, Abdelkader, Yuh, Chao-Yi, Surendranath, Arun, and Singh, Prabhakar. Fri . "Role of Exposure Atmospheres on Particle Coarsening and Phase Transformation of LiAlO 2". United States. doi:10.1149/2.0181708jes. https://www.osti.gov/servlets/purl/1425155.
@article{osti_1425155,
title = {Role of Exposure Atmospheres on Particle Coarsening and Phase Transformation of LiAlO 2},
author = {Heo, Su Jeong and Hu, Boxun and Uddin, Md Aman and Aphale, Ashish and Hilmi, Abdelkader and Yuh, Chao-Yi and Surendranath, Arun and Singh, Prabhakar},
abstractNote = {The phase transformation and particle coarsening of lithium aluminate (α-LiAlO2) in electrolyte are the major causes of degradation affecting the performance and the lifetime of the molten carbonate fuel cell (MCFC). The stability of LiAlO2 has been studied in Li2CO3-Na2CO3 electrolyte under accelerated conditions in reducing and oxidizing gas atmospheres at temperatures of 650 and 750 for up to 500 hours. X-ray diffraction analyses show that the progressive transformation of α-LiAlO2 to γ-LiAlO2 phase proceeds with increasing temperature in lower PCO2 and lower PO2 environments. Spherical LiAlO2 particles were transformed to coarsened pyramid-shape particles in 4% H2-3% H2O-N2 and 100% N2 (~10 ppm PO2 ) atmospheres. Under CO2-rich atmospheres (4% H2-30% CO2-N2 and 70% air-30% CO2), both phase and particle size remained unchanged at 650 and 750ºC. The selected area electron diffraction (SAED) pattern analysis indicated that the large pyramidal shape particles (~30 μm) were γ-LiAlO2 phase. Experimental observations and related simulation results pertaining to particle coarsening and phase transformation behavior of LiAlO2 are presented.},
doi = {10.1149/2.0181708jes},
journal = {Journal of the Electrochemical Society},
number = 8,
volume = 164,
place = {United States},
year = {Fri May 05 00:00:00 EDT 2017},
month = {Fri May 05 00:00:00 EDT 2017}
}

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