Journal article

Publication year: 2019

Pages: 10280-10290

Journal: Journal of Physical Chemistry C

Volume number: 123

Issue number: 16

ISSN: 1932-7447

DOI Link: https://doi.org/10.1021/acs.jpcc.9b01425

Publisher: American Chemical Society

Abstract: 
Glass-ceramic solid electrolytes have been reported to exhibit high ionic conductivities. Their synthesis can be performed by crystallization of mechanically milled Li2S-P2S5 glasses. Herein, the amorphization process of Li2S-P2S5 (75:25) induced by ball milling was analyzed via X-ray diffraction (XRD), Raman spectroscopy, and P-31 magic-angle spinning nuclear magnetic resonance (NMR) spectroscopy. Several structural building blocks such as [P4S10], [P2S6](4-), [P2S7](4-), and [PS4](3-) occur during this amorphization process. In addition, high-temperature XRD was used to study the crystallization process of the mechanically milled Li2S-P2S5 glass. Crystallization of phase-pure beta-Li3PS4 was observed at temperatures up to 548 K. The kinetics of crystallization was analyzed by integration of the intensity of the Bragg reflections. Li-7 NMR relaxometry and pulsed field-gradient (PFG) NMR were used to investigate the short-range and long-range Li+ dynamics in these amorphous and crystalline materials. From the diffusion coefficients obtained by PFG NMR, similar Li+ conductivities for the glassy and heat-treated samples were calculated. For the glassy sample and the glass ceramic beta-Li3PS4 (calcination at 523 K for 1 h), a Li+ bulk conductivity sigma(Li) of 1.6 x 10(-4) S/cm (298 K) was obtained, showing that for this system a well-crystalline material is not essential to achieve fast Li-ion dynamics. Impedance measurements reveal a higher overall conductivity for the amorphous sample, suggesting that the influence of grain boundaries is small in this case.

Harvard Citation style: Stöffler, H., Zinkevich, T., Yavuz, M., Hansen, A., Knapp, M., Bednarcik, J., et al. (2019) Amorphous versus Crystalline Li3PS4: Local Structural Changes during Synthesis and Li Ion Mobility, Journal of Physical Chemistry C, 123(16), pp. 10280-10290. https://doi.org/10.1021/acs.jpcc.9b01425

APA Citation style: Stöffler, H., Zinkevich, T., Yavuz, M., Hansen, A., Knapp, M., Bednarcik, J., Randau, S., Richter, F., Janek, J., Ehrenberg, H., & Indris, S. (2019). Amorphous versus Crystalline Li3PS4: Local Structural Changes during Synthesis and Li Ion Mobility. Journal of Physical Chemistry C. 123(16), 10280-10290. https://doi.org/10.1021/acs.jpcc.9b01425