Both electrodes in one supercapacitor cell were identical.
The electrodes were immersed into 1 M H2SO4 aqueous electrolyte
solution until wetted. A commercial thin paper separator soaked in
the electrolyte solution was used in order to prevent direct contact
between the two electrodes. Finally, the symmetric supercapacitor
device was assembled by sandwiching thepaper separator between
two identical electrodes