The crystal structure and electrical/thermal transport properties of Li1−xSn2+xP2and its performance as a Li-ion battery anode material

Autor: Akira Miura, Yosuke Goto, Takeshi Mito, Hidetomo Usui, Yusuke Nakai, Tatsuma D. Matsuda, Yuji Aoki, Kiyoshi Kanamura, Yoshifumi Nakacho, Yoshikazu Mizuguchi, Chikako Moriyoshi, Shota Nakanishi, Yuto Yamada, Yoshihiro Kuroiwa
Rok vydání: 2021
Předmět:
Zdroj: Journal of Materials Chemistry A. 9:7034-7041
ISSN: 2050-7496
2050-7488
Popis: A new ternary layered pnictide, Li1−xSn2+xP2, was synthesized by a solid-state reaction and its properties were examined to explore its potential as a multifunctional material. The compound crystallizes in a layered structure in the Rm space group (no. 166) with buckled honeycomb Sn–P layers separated by mixed-occupation Li/Sn layers. Crystal structure analysis by synchrotron X-ray diffraction showed that the substitution degree of Li by Sn is x = 0.38. The local ordering of Li/Sn occupation was demonstrated using 31P nuclear magnetic resonance analysis. The thermal and electrical transport properties are significantly affected by this local ordering. The lattice thermal conductivity of Li1−xSn2+xP2 was found to be relatively low (1.2 W m−1 K−1 at 525 K). The room-temperature electrical resistivity of Li1−xSn2+xP2 was found to be 0.3–0.4 mΩ cm and metallic conductivity was observed down to 0.5 K. First-principles calculations demonstrated that the electronic structure and Fermi energy of Li1−xSn2+xP2 are significantly dependent upon x. Moreover, the electronic structure of Li1−xSn2+xP2 is different from that of the related compound NaSn2As2, which shows a superconducting transition. Electrochemical measurements using a single-particle technique demonstrated the activity of Li1−xSn2+xP2 as an anode material for rechargeable Li-ion batteries.
Databáze: OpenAIRE