The Li–C phase equilibria

Abstract

Abstract Experimental work using X-ray diffraction and differential scanning calorimetry was conducted on key samples in the Li–C binary system. Reproducible differential scanning calorimetry data with multiple heating cycles were produced only by samples sealed in arc welded Ta-capsules. Only one compound, α/βLi2C2, is found to be stable. A comprehensive Calphad-type assessment was performed and for the first time a consistent thermodynamic description, covering all thermodynamic and phase equilibrium data, is developed. Phase diagrams calculated from that validated database, including the gas phase, are presented. The phase LiC6, was also studied experimentally. It is metastable with respect to α/βLi2C2 + (C), but may be formed from Li + (C). Phase transitions of LiC6, claimed in the literature, are discussed.