AUTHOR=Xuefu Shang , Nemori Hiroyoshi , Mitsuoka Shigehi , Xu Peng , Matsui Masaki , Takeda Yasuo , Yamamoto Osamu , Imanishi Nobuyuki 

TITLE=High Lithium-Ion-Conducting NASICON-Type Li1+xAlxGeyTi2−x−y(PO4)3 Solid Electrolyte

JOURNAL=Frontiers in Energy Research

VOLUME=4

YEAR=2016

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2016.00012

DOI=10.3389/fenrg.2016.00012

ISSN=2296-598X

ABSTRACT=<p>A water-stable solid electrolyte is a key material without which aqueous lithium–air batteries could not be operated. In this study, we have examined the electrical conductivity and mechanical properties of a water-stable lithium-ion-conducting solid electrolyte, Li<sub>1+</sub><italic><sub><italic>x</italic></sub></italic>Al<italic><sub><italic>x</italic></sub></italic>Ge<italic><sub><italic>y</italic></sub></italic>Ti<sub>2−</sub><italic><sub><italic>x</italic></sub></italic><sub>−</sub><italic><sub><italic>y</italic></sub></italic>(PO<sub>4</sub>)<sub>3</sub> with the NASICON-type structure, as a function of the Al and Ge content. Li<sub>1+</sub><italic><sub><italic>x</italic></sub></italic>Al<italic><sub><italic>x</italic></sub></italic>Ge<italic><sub><italic>y</italic></sub></italic>Ti<sub>2−</sub><italic><sub><italic>x</italic></sub></italic><sub>−</sub><italic><sub><italic>y</italic></sub></italic>(PO<sub>4</sub>)<sub>3</sub> was synthesized by the conventional solid-state reaction method. The highest lithium-ion conductivity of 1.0 × 10<sup>−3</sup> S cm<sup>−1</sup> at 25°C and the highest three-point bending strength of 90 N mm<sup>−2</sup> at room temperature were observed for a pellet of Li<sub>1.45</sub>Al<sub>0.45</sub>Ge<sub>0.2</sub>Ti<sub>1.35</sub>(PO<sub>4</sub>)<sub>3</sub> sintered at 900°C.</p>