Phase stability, electrochemical stability and ionic conductivity of the Li10±1MP2X12 (M = Ge, Si, Sn, Al or P, and X = O, S or Se) family of superionic conductors (original) (raw)
* Corresponding authors
a Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA
E-mail: gceder@mit.edu
b Samsung Advanced Institute of Technology, 1 Cambridge Center, Suite 702, Cambridge, MA 02142, USA
Abstract
We present an investigation of the phase stability, electrochemical stability and Li+ conductivity of the Li10±1MP2X12 (M = Ge, Si, Sn, Al or P, and X = O, S or Se) family of superionic conductors using first principles calculations. The Li10GeP2S12 (LGPS) superionic conductor has the highest Li+ conductivity reported to date, with excellent electrochemical performance demonstrated in a Li-ion rechargeable battery. Our results show that isovalent cation substitutions of Ge4+ have a small effect on the relevant intrinsic properties, with Li10SiP2S12 and Li10SnP2S12 having similar phase stability, electrochemical stability and Li+ conductivity as LGPS. Aliovalent cation substitutions (M = Al or P) with compensating changes in the Li+ concentration also have a small effect on the Li+ conductivity in this structure. Anion substitutions, however, have a much larger effect on these properties. The oxygen-substituted Li10MP2O12 compounds are predicted not to be stable (with equilibrium decomposition energies >90 meV per atom) and have much lower Li+ conductivities than their sulfide counterparts. The selenium-substituted Li10MP2Se12 compounds, on the other hand, show a marginal improvement in conductivity, but at the expense of reduced electrochemical stability. We also studied the effect of lattice parameter changes on the Li+ conductivity and found the same asymmetry in behavior between increases and decreases in the lattice parameters, i.e., decreases in the lattice parameters lower the Li+ conductivity significantly, while increases in the lattice parameters increase the Li+ conductivity only marginally. Based on these results, we conclude that the size of the S2− is near optimal for Li+ conduction in this structural framework.
You have access to this article
Please wait while we load your content... Something went wrong. Try again?
Supplementary files
Article information
DOI
https://doi.org/10.1039/C2EE23355J
Article type
Paper
Submitted
15 Jun 2012
Accepted
01 Oct 2012
First published
02 Oct 2012
Download Citation
Energy Environ. Sci., 2013,6, 148-156
Permissions
Phase stability, electrochemical stability and ionic conductivity of the Li10±1MP2X12 (M = Ge, Si, Sn, Al or P, and X = O, S or Se) family of superionic conductors
S. P. Ong, Y. Mo, W. D. Richards, L. Miara, H. S. Lee and G. Ceder,Energy Environ. Sci., 2013, 6, 148DOI: 10.1039/C2EE23355J
To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.
If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.
If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.
Read more about how to correctly acknowledge RSC content.