skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on May 14, 2019

Title: Enhanced alkaline stability in a hafnium-substituted NaSICON ion conductor

In this paper, we present a multi-length scale integration of compositionally tailored NaSICON-based Na + conductors to create a high Na + conductivity system resistant to chemical attack in strongly alkaline aqueous environments. Using the Pourbaix Atlas as a generalized guide to chemical stability, we identify NaHf 2P 3O 12 (NHP) as a candidate NaSICON material for enhanced chemical stability at pH > 12, and demonstrate the stability of NHP powders under accelerated aging conditions of 80 °C and pH = 13–15 for a variety of alkali metal cations. To compensate for the relatively low ionic conductivity of NHP, we develop a new low temperature (775 °C) alkoxide-based solution deposition chemistry to apply dense NHP thin films onto both platinized silicon wafers and bulk, high Na + conductivity Na 3Zr 2Si 2PO 12 (NZSP) pellets. These NHP films display Na+ conductivities of 1.35 × 10 -5 S cm -1 at 200 °C and an activation energy of 0.53 eV, similar to literature reports for bulk NHP pellets. Under aggressive conditions of 10 M KOH at 80 °C, NHP thin films successfully served as an alkaline-resistant barrier, extending the lifetime of NZSP pellets from 4.26 to 36.0 h. Lastlyl, this integrationmore » of compositionally distinct Na + conductors across disparate length scales (nm, mm) and processing techniques (chemically-derived, traditional powder) represents a promising new avenue by which Na + conducting systems may be utilized in alkaline environments previously thought incompatible with ceramic Na + conductors.« less
Authors:
ORCiD logo [1] ;  [1] ; ORCiD logo [1] ;  [1] ; ORCiD logo [1]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
Report Number(s):
SAND-2018-13334J
Journal ID: ISSN 2050-7488; JMCAET; 670303
Grant/Contract Number:
AC04-94AL85000; NA0003525
Type:
Accepted Manuscript
Journal Name:
Journal of Materials Chemistry. A
Additional Journal Information:
Journal Volume: 6; Journal Issue: 20; Journal ID: ISSN 2050-7488
Publisher:
Royal Society of Chemistry
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE Office of Electricity Delivery and Energy Reliability (OE); USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE
OSTI Identifier:
1485832
Alternate Identifier(s):
OSTI ID: 1437064

Small, Leo J., Wheeler, Jill S., Ihlefeld, Jon F., Clem, Paul G., and Spoerke, Erik David. Enhanced alkaline stability in a hafnium-substituted NaSICON ion conductor. United States: N. p., Web. doi:10.1039/C7TA09924J.
Small, Leo J., Wheeler, Jill S., Ihlefeld, Jon F., Clem, Paul G., & Spoerke, Erik David. Enhanced alkaline stability in a hafnium-substituted NaSICON ion conductor. United States. doi:10.1039/C7TA09924J.
Small, Leo J., Wheeler, Jill S., Ihlefeld, Jon F., Clem, Paul G., and Spoerke, Erik David. 2018. "Enhanced alkaline stability in a hafnium-substituted NaSICON ion conductor". United States. doi:10.1039/C7TA09924J.
@article{osti_1485832,
title = {Enhanced alkaline stability in a hafnium-substituted NaSICON ion conductor},
author = {Small, Leo J. and Wheeler, Jill S. and Ihlefeld, Jon F. and Clem, Paul G. and Spoerke, Erik David},
abstractNote = {In this paper, we present a multi-length scale integration of compositionally tailored NaSICON-based Na+ conductors to create a high Na+ conductivity system resistant to chemical attack in strongly alkaline aqueous environments. Using the Pourbaix Atlas as a generalized guide to chemical stability, we identify NaHf2P3O12 (NHP) as a candidate NaSICON material for enhanced chemical stability at pH > 12, and demonstrate the stability of NHP powders under accelerated aging conditions of 80 °C and pH = 13–15 for a variety of alkali metal cations. To compensate for the relatively low ionic conductivity of NHP, we develop a new low temperature (775 °C) alkoxide-based solution deposition chemistry to apply dense NHP thin films onto both platinized silicon wafers and bulk, high Na+ conductivity Na3Zr2Si2PO12 (NZSP) pellets. These NHP films display Na+ conductivities of 1.35 × 10-5 S cm-1 at 200 °C and an activation energy of 0.53 eV, similar to literature reports for bulk NHP pellets. Under aggressive conditions of 10 M KOH at 80 °C, NHP thin films successfully served as an alkaline-resistant barrier, extending the lifetime of NZSP pellets from 4.26 to 36.0 h. Lastlyl, this integration of compositionally distinct Na+ conductors across disparate length scales (nm, mm) and processing techniques (chemically-derived, traditional powder) represents a promising new avenue by which Na+ conducting systems may be utilized in alkaline environments previously thought incompatible with ceramic Na+ conductors.},
doi = {10.1039/C7TA09924J},
journal = {Journal of Materials Chemistry. A},
number = 20,
volume = 6,
place = {United States},
year = {2018},
month = {5}
}