Crystal Chemistry of Argyrodites and A₃PS₄-Type Solid Electrolytes (A=Li, Na) for Batteries

Solid electrolytes are crucial for next-generation solid-state batteries and immense activity is going on worldwide on many structural families of interest, including the ionic conductors Na₃PS₄, Li₃PS_4, Li₄PS₄I and Argyrodite Li₆PS₅(Cl,Br,I). We will present our recent crystal chemistry findings on these materials.

Li₃PS₄ is an attractive solid-electrolyte material that possesses high RT ionic conductivity (10^-4 S.cm⁻¹) but the effects of specific synthesis parameters on the material's local structure and transport properties still demand clarifications. In particular, mechano-chemistry induces the formation of a variety of P_xS_y^a− moieties that strongly influence the global transport properties of Li₃PS_4.

Na₃PS₄ is another very interesting material with complex crystal chemistry that we will present. The effects of mechanochemical synthesis that lead to increased ionic conductivity in an archetypical sodium ion conductor Na₃PS₄ were not fully understood and we undertook comprehensive analysis based on diffraction (Bragg and pair distribution function), spectroscopy (impedance, Raman, NMR and INS), and ab initio simulations.

References
Ö. U. Kudu, T. Famprikis, S. Cretu, B. Porcheron, E. Salager, A. Demortiere, M. Courty, V. Viallet, T. Le Mercier, B. Fleutot, M.D. Braida & C. Masquelier, Energy Storage Materials, 44, 168-179 (2022)
T. Famprikis, H. Bouyanfif, P. Canepa, M. Zbiri, J. Dawson, E. Suard, F. Fauth, H. Playford, D. Dambournet, O. Borkiewicz, M. Courty, O. Clemens, J.N. Chotard, M.S. Islam & C. Masquelier, Chem. Mater., 33(14), 5652-5667 (2021)
T. Famprikis, U. Kudu, J. Dawson, P. Canepa, F. Fauth, E. Suard, M. Zbiri, D. Dambournet, O. Borkiewicz, H. Bouyanfif, S. Emge, C. Grey, S. Cretu, J.N. Chotard, W. Zeier, M. S. Islam & C. Masquelier, J. Amer. Chem. Soc., 142(43), 18422-18436 (2020)