Investigation of lithium carbide contamination in battery grade lithium metal

Schmitz R, Muller R, Kruger S, Schmitz RW, Nowak S, Passerini S, Winter M, Schreiner C

Abstract

Lithium carbide has been found as possible contamination in high purity lithium metal. Raman spectroscopy clearly shows its presence on the surface as well as in the bulk. Mass spectrometry revealed the formation of acetylene during hydrolization of lithium metal also for the bulk material. The total lithium content of the lithium sample is determined with ICP-OES and the ratio of oxygen to carbon is investigated with EDX for the surface and the bulk. Possible sources of the lithium carbide contamination in battery grade lithium are discussed. Highlights: Lithium carbide has been found as impurity in battery grade lithium metal. Detection of Li 2C 2 on the lithium surface and in the bulk material. Analysis by Raman spectroscopy, mass spectrometry, ICP-OES, and EDX. Discussion of possibilities for the source of contamination. © 2012 Elsevier B.V. All rights reserved.