Information　about　the　thermodynamic　stability　of　LiC6　in　the　literature　is　ambiguous　at　present.　The　thermodynamic　stability　of　LiC6　and　Li2C2　is　investigated　by　an　approach　combining　differential　scanning　calorimetry　(DSC),　X-ray　diffraction　(XRD)　and　long-time　annealing　experiments.　It　is　found　that　LiC6　is　thermodynamically　unstable　above　330　degrees　C,　where　in　the　corresponding　composition　range　Li2C2　and　graphite　are　in　thermodynamic　equilibrium.　During　heating,　a　de-intercalation　process　is　observed　in　LiC6,　and　eventually　a　transformation　to　Li2C2　and　graphite.　The　enthalpy　of　formation　of　LiC6　is　below　zero　as　it　forms　from　the　pure　components,　the　limits　of　the　enthalpy　of　formation　are　set　by　the　tangents　to　the　enthalpies　of　formation　of　Li2C2　and　graphite.　An　order-disorder　transition　in　LiC6　was　not　observed.　(C)　2013　Elsevier　B.V.　All　rights　reserved.