Abstract
It is suggested that in practical nonaqueous battery systems the alkali and alkaline earth metals are always covered by a surface layer which is instantly formed by the reaction of the metal with the electrolyte. This layer, which acts as an interphase between the metal and the solution, has the properties of a solid electrolyte. The corrosion rate of the metal, the mechanism of the deposition‐dissolution process, the kinetic parameters, the quality of the metal deposit, and the half‐cell potential depend on the character of the solid electrolyte interphase (SEI).