Time-Dependent Determination of HF Formation in LiPF6 -Containing Electrolytes in Different Cell Types by Spectroscopic Ellipsometry

Abstract

A novel experimental technique was developed to investigate HF formation in organic carbonate based electrolytes containing LiPF6. Using spectroscopic ellipsometry, aging and thermal decomposition of the electrolyte were monitored in a standard glass cell and in a polypropylene vessel. The amount of HF generated was determined by following the etching rate of a thin silicon dioxide layer on a silicon wafer in contact with the electrolyte. The material of cell construction clearly influenced the etching rate of the SiO2 sensor and affected the rate of degradation.