Towards a Practical Use of Sulfide Solid Electrolytes in Solid‐State Batteries: Impact of Dry Room Exposure on H<sub>2</sub>S Release and Material Properties
Xavier Randrema, Ivan Leteyi Mfiban, Marine Soler, Irina Profatilova, Manon Berthault, R. Ramos, J.M. Lavie, Éric De Vito, Lionel Blanc, Sébastien Diry, Sébastien Launois, Vasily Tarnopolskiy, M. Reytier, J. Colin, Céline Barchasz, Sébastien Liatard
Abstract
Abstract Sulfide‐based solid electrolytes (SEs) are amongst the most promising solid electrolytes for the development of solid‐state batteries (SSBs) due to their high ionic conductivity and processing advantage over oxide‐based SEs. However, one of the main drawbacks of sulfide SEs is their rapid degradation in presence of humidity. In this study, we investigated the effect of exposing three different sulfide SEs (Li 7 P 3 S 11 , the argyrodite Li 6 PS 5 Cl and the chloride‐doped argyrodite Li 6‐ x PS 5‐ x Cl 1+ x ) to the atmosphere of a dry room at a dew point (DP)=−40 °C. For the first time to the best of our knowledge, enhanced infra‐red (IR) laser technology was employed to follow and quantify online and in‐situ H 2 S evolution by the SEs in a dry room environment over 16 h. It was found that argyrodite compounds evolved approximately 8 times less H 2 S compared to Li 7 P 3 S 11 over 16 h of exposure with peak concentrations between 5 and 16 ppm vol. The exposed materials were studied using X‐ray diffraction, Raman spectroscopy, electrochemical impedance spectroscopy, X‐ray photoelectron spectrometry (XPS) and galvanostatic cycling. XPS results revealed a formation of Li 2 CO 3 on the surface of argyrodite SEs, which served as a robust passivation layer limiting considerably reactions with the dry room atmosphere.