Electronic Structures and Geometry of CuSn as an Anode Material for Lithium Batteries

The mixed-basis expansion of the wave-function together with the first-principles norm-conserving non-local pseudopotentials method has been used to study the electronic structures and geometric properties of CuSn under various structures, i.e. the NaCl-type, CsCl-type, Zinc-blende-type, WC-type, NiAs-type structures and tetragonal structure, which changes along the C-axis based on the CsCl structure. The relationship between the cohesive energies and the volumes of different structures, i.e. the energy-structure phase diagram, is presented. The result shows the NiAs-structure at low temperature is the most stable structure of CuSn. Furthermore, the band structures, electronic densities of states, charge density contour plots and bonding characters for CuSn crystallized in NiAs structure are also discussed. It is shown that the calculated stable phase for CuSn is consistent with the experiment result.