Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Mar 17:7:11009.
doi: 10.1038/ncomms11009.

Design and synthesis of the superionic conductor Na10SnP2S12

William D Richards  1 , Tomoyuki Tsujimura  2 , Lincoln J Miara  3 , Yan Wang  1 , Jae Chul Kim  1   4 , Shyue Ping Ong  5 , Ichiro Uechi  2 , Naoki Suzuki  2 , Gerbrand Ceder  1   4   6
Affiliations

Design and synthesis of the superionic conductor Na10SnP2S12

William D Richards et al. Nat Commun. .

Abstract

Sodium-ion batteries are emerging as candidates for large-scale energy storage due to their low cost and the wide variety of cathode materials available. As battery size and adoption in critical applications increases, safety concerns are resurfacing due to the inherent flammability of organic electrolytes currently in use in both lithium and sodium battery chemistries. Development of solid-state batteries with ionic electrolytes eliminates this concern, while also allowing novel device architectures and potentially improving cycle life. Here we report the computation-assisted discovery and synthesis of a high-performance solid-state electrolyte material: Na10SnP2S12, with room temperature ionic conductivity of 0.4 mS cm(-1) rivalling the conductivity of the best sodium sulfide solid electrolytes to date. We also computationally investigate the variants of this compound where tin is substituted by germanium or silicon and find that the latter may achieve even higher conductivity.

PubMed Disclaimer

Figures

Figure 1
Figure 1. Structure of Na10SnP2S12 from DFT calculations.
Sodium occupancies are calculated from 600 K AIMD simulation (see Methods). All ground-state NMPS structures share this M/P ordering, which reduces the symmetry from the P42/nmc space group to formula image, separating each Na-site into two symmetrically distinct but similar sites marked as a and b. PS4 tetrahedra are marked in purple, SnS4 tetrahedra in blue and Na-sites in yellow. The ground-state Na-ordering is shown in Supplementary Fig. 2.
Figure 2
Figure 2. DFT computed diffusivity of Na10SnP2S12.
(a) Na-diffusivity in Na10SiP2S12, Na10GeP2S12 and Na10SnP2S12 from AIMD simulation. Dashed lines are Arrhenius fits to the data, and error bars are standard error of the mean. (b) Na-ion probability density isosurface (yellow) of Na10SnP2S12 from 600 K AIMD simulation. SnS4 tetrahedra are marked in blue, PS4 tetrahedra in purple.
Figure 3
Figure 3. Na-Sn-P-S phase diagram.
Pseudo-ternary 0 K Na-Sn-P-S phase diagram constructed from DFT energy calculations, with location of Na10SnP2S12. Stable phases marked with blue dot.
Figure 4
Figure 4. Experimental crystal structure and diffusivity of Na10SnP2S12.
(a) Experimental and simulated XRD patterns of Na10SnP2S12, showing small amounts of recrystallized P2S5, Na3PS4 and Na2S. (b) Diffusivity calculated from experimentally measured ionic conductivity versus temperature. Dashed line is an Arrhenius fit to the data. (inset) Electrochemical impedance spectroscopy measurements.
Figure 5
Figure 5. Na-site occupancy analysis of NMPS structures.
(a) Occupancy of Na sites in Na10SiP2S12, Na10GeP2S12 and Na10SnP2S12 from AIMD simulation between 600 and 1,300 K, after imposing P42/nmc spacegroup operations. The site occupancies in the Na-chain (Na1 and Na3) have been combined for clarity. (b) Illustration of the Na-chain, Na-crossover and Na-immobile sites. SnS4 and PS4 tetrahedra (grey), all spheres are Na-sites.
See this image and copyright information in PMC

References

    1. Ellis B. L. & Nazar L. F. Sodium and sodium-ion energy storage batteries. Curr. Opin. Solid State Mater. Sci. 16, 168–177 (2012).
    1. Kim S.-W., Seo D.-H., Ma X., Ceder G. & Kang K. Electrode materials for rechargeable sodium-ion batteries: potential alternatives to current lithium-ion batteries. Adv. Energy Mater. 2, 710–721 (2012).
    1. Pan H., Hu Y.-S. & Chen L. Room-temperature stationary sodium-ion batteries for large-scale electric energy storage. Energy Environ. Sci. 6, 2338 (2013).
    1. Ponrouch A., Marchante E., Courty M., Tarascon J.-M. & Palacn M. R. In search of an optimized electrolyte for Na-ion batteries. Energy Environ. Sci. 5, 8572 (2012).
    1. Komaba S. et al.. Electrochemical Na insertion and solid electrolyte interphase for hard-carbon electrodes and application to Na-ion batteries. Adv. Funct. Mater. 21, 3859–3867 (2011).

Publication types