On the statistical mechanics investigation of structure and effective electrostatic force differential capacitance does not drop significantly with decreasing the supercapacitor size and implies one potential application in promoting the EDL energy storage by reducing the device size and dissolving the electrolyte with the present model solvent. (iii) New and novel features of the SEF include the insensitivity of the SEF curve to the bulk electrolyte concentration and like charge attraction in the 1:1 electrolyte; moreover, the SEF strength always drops definitely with the solvent site polarization charge strength. (iv) It is argued that the underlying causes of the above observations are the solvent chain structure and solvent site polarization charge, which highlights several unique effects: space congestion, interparticle association in the EDL, additional electrostatic screening caused by the polarized solvent site, and 'bridge' force and the entropic force due to the chain structure.