First-principles insight into Li and Na ion storage in graphene oxide |
Relaxed configurations of a Li atom on GO with different O/C ratios: (a) 12.5% (C8O1), (b) 25% (C8O2), (c) 37.5% (C8O3), and (d) 50% (C8O4). The grey spheres stand for C atoms, the red spheres for O atoms, and the purple spheres for Li. |