Fig. 2

Intercalation of alkali-metal cations into graphene slit pores. a Potential energy surface computed for the intercalation of the Li\({}^{+}\), Na\({}^{+}\), K\({}^{+}\), and Cs\({}^{+}\) ions into a graphene slit pore with a pore diameter of \(d=6\) Å and an excess charge of \({q}_{{\rm{grp}}}=-1e\). The pore is at left, the bulk solution is at right, and the dashed line indicates the location of edge hydrogen atoms at the pore opening. b Computed ionic charges and electronic density of the cation-intercalated graphene slit pores with the isosurface value set to 5\(\times\)10\({}^{-3}\) a.u., and schematic description of confinement effects on the cation adsorption position and charge transfer