SURFACE CHEMICAL PROCESSES OF CLEAN LITHIUM: SMALL MOLECULE AND SOLID STATE CORROSION REACTIONS RELEVANT TO THE Li/SO//2 BATTERY.

Self-discharge/corrosion reactions of clean lithium in environments which model Li/SO//2 batteries have been studied. Removal of the interface in question to ultrahigh vacuum, subsequent dosing with gases and liquids, and examination by XPS has been carried out to characterize the near surface regions, which are short-lived and difficult to study in real-world systems. Semi-passive layers which form on the lithium surface in contact with SO//2, SO//2-saturated CH//3CN, etc. are different than previously diagnosed by post-mortem examination of electrochemical cells. Corrosion of SiO//2 by Li degree proceeds by reduction of the matrix and formation of products not predicted from purely thermodynamic considerations.