Corrosion of aluminum at high voltages in non-aqueous electrolytes containing perfluoroalkylsulfonyl imides; new lithium salts for lithium-ion cells

New lithium bis-perfluoroalkylsulfonyl imide salts were recently synthesized in our laboratories whose properties make them promising candidates for lithium-ion batteries. The salts have good conductivity, cycling characteristics and excellent thermal and hydrolytic stability. In the focus of this paper are the corrosion properties of the aluminum current collector in electrolytes based on these salts. High protection potentials at aluminum in bisperfluoroethylsulfonyl imide electrolytes were observed. Based on the surface analysis of the protective film, a correlation of the molecular weight of the anions to their protective properties was established.