TY - JOUR
T1 - Sodium and magnesium ionic conduction in complex hydrides
AU - Matsuo, Motoaki
AU - Oguchi, Hiroyuki
AU - Sato, Toyoto
AU - Takamura, Hitoshi
AU - Tsuchida, Eiji
AU - Ikeshoji, Tamio
AU - Orimo, Shin Ichi
N1 - Funding Information:
The authors would like to thank Ms. N. Warifune and Ms. H. Ohmiya for their technical support. This work was partly performed under the co-operative research program of Advanced Research Center of Metallic Glasses, IMR of Tohoku University. This research was funded by KAKENHI (18GS0203 and 22760529), “Funding Program for Next Generation World-Leading Researchers (GR008)”.
PY - 2013
Y1 - 2013
N2 - Sodium and magnesium ionic conduction in complex hydrides as a new category of solid-state fast ionic conductors is presented. We first investigated experimentally the sodium ionic conductivities of the representative Na-based complex hydrides NaBH4, NaNH2, NaAlH4, and Na3AlH6, all of which have single complex anion [BH 4]-, [NH2]-, [AlH4] - and [AlH6]3-, respectively. Na 3AlH6 showed much higher ionic conductivity of 5 × 10-7 S/cm at 300 K than NaBH4, NaNH2, and NaAlH4 (their ionic conductivities were around 10-10 S/cm). We obtained the sodium fast-ionic conductor Na2(BH 4)(NH2) with the [BH4]- and [NH 2]- complex anions by combining NaBH4 and NaNH2 with a molar ratio of 1:1. It exhibited the most superior sodium ionic conductivity of 3 × 10-6 S/cm at 300 K because of the specific antiperovskite-type structure with vacancies in the Na+ site. Furthermore, first-principles molecular dynamics simulations suggested the possible magnesium ionic conduction in the high-temperature phase of Mg(BH 4)2 by substituting partly [BH4]- with [AlH4]-.
AB - Sodium and magnesium ionic conduction in complex hydrides as a new category of solid-state fast ionic conductors is presented. We first investigated experimentally the sodium ionic conductivities of the representative Na-based complex hydrides NaBH4, NaNH2, NaAlH4, and Na3AlH6, all of which have single complex anion [BH 4]-, [NH2]-, [AlH4] - and [AlH6]3-, respectively. Na 3AlH6 showed much higher ionic conductivity of 5 × 10-7 S/cm at 300 K than NaBH4, NaNH2, and NaAlH4 (their ionic conductivities were around 10-10 S/cm). We obtained the sodium fast-ionic conductor Na2(BH 4)(NH2) with the [BH4]- and [NH 2]- complex anions by combining NaBH4 and NaNH2 with a molar ratio of 1:1. It exhibited the most superior sodium ionic conductivity of 3 × 10-6 S/cm at 300 K because of the specific antiperovskite-type structure with vacancies in the Na+ site. Furthermore, first-principles molecular dynamics simulations suggested the possible magnesium ionic conduction in the high-temperature phase of Mg(BH 4)2 by substituting partly [BH4]- with [AlH4]-.
KW - Complex hydride
KW - Magnesium ionic conduction
KW - Sodium ionic conduction
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U2 - 10.1016/j.jallcom.2013.01.058
DO - 10.1016/j.jallcom.2013.01.058
M3 - Article
AN - SCOPUS:84886594389
SN - 0925-8388
VL - 580
SP - S98-S101
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
IS - SUPPL1
ER -