AUTHOR=Hori Satoshi , Suzuki Kota , Hirayama Masaaki , Kato Yuki , Kanno Ryoji 

TITLE=Lithium Superionic Conductor Li9.42Si1.02P2.1S9.96O2.04 with Li10GeP2S12-Type Structure in the Li2S–P2S5–SiO2 Pseudoternary System: Synthesis, Electrochemical Properties, and Structure–Composition Relationships

JOURNAL=Frontiers in Energy Research

VOLUME=4

YEAR=2016

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2016.00038

DOI=10.3389/fenrg.2016.00038

ISSN=2296-598X

ABSTRACT=<p>Lithium superionic conductors with the Li<sub>10</sub>GeP<sub>2</sub>S<sub>12</sub> (LGPS)-type structure are promising materials for use as solid electrolytes in the next-generation lithium batteries. A novel member of the LGPS family, Li<sub>9.42</sub>Si<sub>1.02</sub>P<sub>2.1</sub>S<sub>9.96</sub>O<sub>2.04</sub> (LSiPSO), and its solid solutions were synthesized by quenching from 1273 K in the Li<sub>2</sub>S–P<sub>2</sub>S<sub>5</sub>–SiO<sub>2</sub> pseudoternary system. The material exhibited an ionic conductivity as high as 3.2 × 10<sup>−4</sup> S cm<sup>−1</sup> at 298 K, as well as the high electrochemical stability to lithium metal, which was improved by the introduction of oxygen into the LGPS-type structure. An all-solid-state cell with a lithium metal anode and LSiPSO as the separator showed excellent performance with a high reversibility of 100%. Thus, oxygen doping is an effective way of improving the electrochemical stability of LGPS-type structure.</p>