Comparison of computational methods for the electrochemical stability window of solid-state electrolyte materials

Abstract

Superior stability and safety are key promises attributed to all-solid-state batteries (ASSBs) containing solid-state electrolyte (SSE) compared to their conventional counterparts utilizing liquid electrolyte. To unleash the full potential of ASSBs, SSE materials that are stable when in contact with the low and high potential electrodes are required. The electrochemical stability window is conveniently used to assess the SSE-electrode interface stability. In the present work, we review the most important methods to compute the SSE stability window. Our analysis reveals that the stoichiometry stability method represents a bridge between HOMO-LUMO method and phase stability method (grand canonical phase diagram). Moreover, we provide computational implementations of these methods for SSE material screening. We compare 1 arXiv:1901.02251v2 [cond-mat.mtrl-sci] 25 Oct 2019 their results for the relevant Li-and Na-SSE materials LGPS, LIPON, LLZO, LLTO, LATP, LISICON, and NASICON, and we discuss their relation to published experimental stability windows.

Sulfide and Oxide Inorganic Solid Electrolytes for All-Solid-State Li Batteries: A Review

“…In addition, Binninger et al [276] performed computational studies on the electrochemical stability voltage window of these electrolytes. (iii) The experimental observations were further validated by the results of the computational study performed by Jay et al [472].…”

“…Computational studies offered further insight into the size of the bottleneck and indicated a possible increased using large rare-earth or alkaline-earth metal ions as A-site ions; moreover, changing the bond strength between the B-site cations and O also affects the conductivity of these electrolytes. In addition, Binninger et al [276] performed computational studies on the electrochemical stability voltage window of these electrolytes.…”

“…Their computational studies were very useful for researchers studying sulfide electrolytes and led to better understanding of the stability of the electrolyte and electrode materials. In addition, Hu et al [ 274 ] and Du et al [ 275 ] performed computational analysis on LGPS-type structures, Binninger et al [ 276 ] investigated the electrochemical stability window of LGPS-type structures, and Gorai et al [ 277 ] performed electronic structure and defect chemistry calculations for LGPS-type structures.…”

“…Moreover, de Klerk and Wagemaker [ 343 ] reported the mathematical space charge model of the LLZO electrolyte and electrode materials, such as graphite and LCO. In addition, Binninger et al [ 276 ] determined the electrochemical stability window of the LLZO electrolyte using computational techniques. Few other reports on doping Li 7 -garnet series have been recently published [ 344 , 345 , 346 , 347 ].…”

“…Li 11−x M 2−x P 1+x S 12 (M = Ge, Sn, Si) (LGPS)-Type StructuresIn 2011, Kamaya et al[266] synthesized the Li 10 GeP 2 S 12 (LGPS) solid electrolyte and reported a conductivity of 9 × 10 -3 S cm −1(Table 1)and electrochemical properties of a LiCoO 2 -LGPS|LGPS|In cell. Moreover, other researchers have extensively analyzed this system[267][268][269][270][271][272][273][274][275][276][277].LGPS presented tetragonal crystal structure with the lattice parameters a = 8.708 Å and c = 12.605 Å and consisted of negatively charged PS4 3− and GeS 4 4− tetrahedra surrounded by (mobile) Li + ions for charge compensation as shown inFigure 17a,and X-ray powder diffraction patterns and Rietveld refinements of Li 11 Si 2 PS 12 and Li 10 SnP 2 S 12 are compared with those previously reported for Li 10 GeP 2 S 12 and Li 7 GePS 8 in…”