Chemically Evolved Composite Lithium-Ion Conductors with Lithium Thiophosphates and Nickel Sulfides

• Published in: ACS energy letters 2017-08, Vol.2 (8), p.1740-1745
• Main Authors: Park, Mansoo, Jung, Hun-Gi, Jung, Wo Dum, Cho, Soo Young, Yun, Bin-Na, Lee, Yoon Sung, Choi, Sungjun, Ahn, Junsung, Lim, Jaemin, Sung, Ju Young, Jang, Yong-Jun, Ahn, Jae-Pyoung, Lee, Jong-Ho, Kim, Hyoungchul
• Format: Article
• Language: English
• ISSN: 2380-8195; 2380-8195
• DOI: 10.1021/acsenergylett.7b00497

The development and application of all-solid-state batteries with a fast lithium-ionic conductor are hampered by structural instability and rigid stoichiometry restrictions. Here, we present a family of lithium thiophosphate prototypes with a novel principle, controlling sulfur deficiencies with the addition of nickel sulfide-based additives, for fast lithium-ion conduction and distinct electrochemical stability under the extended material constituent. Well-controlled sulfur deficiency of the Li3PS4 framework accompanied by nickel sulfide additive offers the notable increase of lithium-ion conductivity (2 × 10–3 S cm–1 at 25 °C) and high electrochemical stability (up to 10 V vs Li/Li+) in a wide composition range. We further confirm the potential application of our fast composite lithium-ion conductor as an electrolyte for the all-solid-state battery with 117 mAh g–1 capacity delivery and stable cycle life.