Evaluation of the Solid-Electrolyte Interphase Formed in the Carbonate-Based Electrolytes with Different Lithium Salts Using the Redox Probe Method

Abstract

The formation of solid-electrolyte interphase (SEI) on a Pt electrode was investigated in ethylene carbonate (EC) and diethyl carbonate (DEC) containing LiPF₆ and lithium bis(trifluoromethylsulfonyl)amide (LiTFSA) using the redox probe method. The formation and properties of the SEI were examined in the electrolytes containing ferrocene as a redox probe. Inhomogeneous and rigid SEI was found to form in 1 M (= mol dm⁻³) LiPF₆/EC+DEC, probably due to the conversion of decomposition products to LiF by the reaction with HF derived from LiPF₆. On the other hand, the formation of homogeneous and soluble (or dispersible) SEI was suggested in 1 M LiTFSA/EC+DEC.