TY - JOUR
T1 - A dramatic reduction in the sintering temperature of the refractory sodium β′′-alumina solid electrolyteviacold sintering
AU - Grady, Zane
AU - Ndayishimiye, Arnaud
AU - Randall, Clive
N1 - Funding Information:
The authors (CAR, ZG) would like to gratefully acknowledge the Pacific Northwest National Laboratory and Battelle Corporation for providing financial support (Contract no. 500819). The authors (CAR, AN) would also like to thank the Air Force Office of Scientific Research (FA9550-19-1-0372) for financial support for FTIR characterization. The authors also thank Dr Andrey Poletayev, Dr David Reed, and Dr Xiaolin Li for insightful technical discussions. The authors would also like to acknowledge Dr Jennifer Gray and Dr Zhongming Fan for their aid in performing cryogenic TEM for this study. The authors would also like to thank the anonymous reviewers for helpful comments and insight.
Publisher Copyright:
© The Royal Society of Chemistry 2021.
PY - 2021/10/14
Y1 - 2021/10/14
N2 - The cold sintering process is successfully applied to one of the most refractory solid-state sodium-ion electrolytes, namely sodium beta alumina (SBA). By using a hydroxide-based transient solvent, SBA is densified below 400 °C, whereas conventional solid-state sintering is known to require sintering temperatures around 1600 °C. This dramatic reduction in sintering temperature (ca. Tsinter∼ 20% ofTm) is achieved by cold sintering with the addition of 10 wt% solid NaOH transient phase, 360 MPa of uniaxial pressure, and heating to 350-375 °C, for a dwell time of three hours. The resulting pellets exceed 90% of the theoretical density for SBA and exhibit ionic conductivities of ∼10−2S cm−1at 300 °C, as measured by electrochemical impedance spectroscopy. The structural changes occurring during cold sintering are reversed with an intermediate temperature annealing step (ca.1000 °C) which improves the ionic conductivity. This study therefore highlights the opportunities and remaining challenges in applying cold sintering to refractory, air-sensitive, electroceramics.
AB - The cold sintering process is successfully applied to one of the most refractory solid-state sodium-ion electrolytes, namely sodium beta alumina (SBA). By using a hydroxide-based transient solvent, SBA is densified below 400 °C, whereas conventional solid-state sintering is known to require sintering temperatures around 1600 °C. This dramatic reduction in sintering temperature (ca. Tsinter∼ 20% ofTm) is achieved by cold sintering with the addition of 10 wt% solid NaOH transient phase, 360 MPa of uniaxial pressure, and heating to 350-375 °C, for a dwell time of three hours. The resulting pellets exceed 90% of the theoretical density for SBA and exhibit ionic conductivities of ∼10−2S cm−1at 300 °C, as measured by electrochemical impedance spectroscopy. The structural changes occurring during cold sintering are reversed with an intermediate temperature annealing step (ca.1000 °C) which improves the ionic conductivity. This study therefore highlights the opportunities and remaining challenges in applying cold sintering to refractory, air-sensitive, electroceramics.
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U2 - 10.1039/d1ta05933e
DO - 10.1039/d1ta05933e
M3 - Article
AN - SCOPUS:85116923402
SN - 2050-7488
VL - 9
SP - 22002
EP - 22014
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 38
ER -