First-principles insight into Li and Na ion storage in graphene oxide
Zhong Shu-Ying, Shi Jing, Luo Wen-Wei, Lei Xue-Ling †
       

Relaxed configurations of GO with epoxy groups with different O/C ratios: (a) 12.5% (C8O1), (b) 25% (C8O2), (c) 37.5% (C8O3), and (d) 50% (C8O4). Grey spheres represent C atoms, and red spheres represent O atoms.