  Density function theory calculations were carried out to clarify storage
states of Lithium (Li) ions in graphene clusters. The adsorption energy, spin
polarization, charge distribution, electronic gap, surface curvature and dipole
momentum were calculated for each cluster. Li-ion adsorbed graphene, doped by
one Li atom is spin polarized, so there would be different gaps for different
spin polarization in electrons. Calculation results demonstrated that a smaller
cluster between each two larger clusters is preferable, because it could
improve graphene Li-ion batteries; consequently, the most proper graphene anode
structure has been proposed.
