Molecular theory of an electrochemical double layer in a nanoporous carbon supercapacitor

We develop the replica RISM theory of electrolyte solution sorbed in a nanoporous carbon electrode. The model comprises carbon nanospheres forming a disordered network with the porosity, pores sizes and surface area fitted to carbonized polyvinylidene chloride (PVDC) material, and to activated carbon. We obtained the huge capacitance comparable to that achieved in supercapacitors, and found the higher capacitance per pores surface for carbonized PVDC material with uniform nanoporous texture than for activated carbon with micro- as well as nanopores. Unlike a planar electrochemical double layer with the voltage dominated by the inner layer, the nanoporous supercapacitor voltage is driven by the solvation chemical potentials of the sorbed ions. (C) 2003 Elsevier B.V. All rights reserved.