Can Substitutions Affect the Oxidative Stability of Lithium Argyrodite Solid Electrolytes?

Ananya Banik, Yunsheng Liu, Saneyuki Ohno, Yannik Rudel, Alberto Jiménez-Solano, Andrei Gloskovskii, Nella M. Vargas-Barbosa, Yifei Mo, Wolfgang G. Zeier

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Lithium-ion conducting argyrodites are among the most studied solid electrolytes due to their high ionic conductivities. A major concern in a solid-state battery is the stability of the solid electrolyte. Here, we present a systematic study on the influence of cationic and anionic substitution on the electrochemical stability of Li6PS5X using stepwise cyclic voltammetry, optical band gap measurements, and hard X-ray photoelectron spectroscopy along with first-principles calculations. We observe that on going from Li6PS5Cl to Li6+xP1-xMxS5I (M = Si4+, Ge4+), the oxidative stability does not change. Considering the chemical bonding shows that the valence band edges are mostly populated by nonbonding orbitals of the PS43- units or unbound sulfide anions and that simple substitutions in these sulfide-based solid electrolytes cannot improve oxidative stabilities. This work provides insights into the role of chemical bonding on the stability of superionic conductors and shows that alternative strategies are needed for long-term stable solid-state batteries.

Original languageEnglish
Pages (from-to)2045-2053
Number of pages9
JournalACS Applied Energy Materials
Volume5
Issue number2
DOIs
Publication statusPublished - Feb 28 2022

All Science Journal Classification (ASJC) codes

  • Chemical Engineering (miscellaneous)
  • Energy Engineering and Power Technology
  • Electrochemistry
  • Electrical and Electronic Engineering
  • Materials Chemistry

Fingerprint

Dive into the research topics of 'Can Substitutions Affect the Oxidative Stability of Lithium Argyrodite Solid Electrolytes?'. Together they form a unique fingerprint.

Cite this