An ultrahigh vacuum reaction chamber/transfer mechanism attached to an Auger electron spectrometer for the study of the reactions of clean lithium surfaces

Abstract

An ultrahigh vacuum reaction chamber/transfer system is described which is used for the production of clean lithium and other soft group I metals. The system is used to study the reactions of clean lithium surfaces with small molecules of interest in electrochemical applications. Auger electron spectroscopy, in a spectrometer coupled to this chamber, shows that the product of the reaction of SO2 with the clean Li surface is a combination of Li2S and Li2O in a 1 : 2 ratio. The transfer system/reaction chamber also allows for the study of the rates of reaction of small molecules with the clean surface. Mechanical scraping of the metal transforms the passive surface into the active, clean state. Study of the SO2/Li reactions at a variety of temperatures (made possible by the special temperature control in the reaction chamber) shows a low activation energy for the dissociation reaction (2–5 kcal/mol).