a b s t r a c t
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 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.
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