Marcelis Muriel1 Rajaram Narayanan1 Prab Bandaru1

1, University of California, San Diego, La Jolla, California, United States

The net capacitance obtainable from activated carbon (AC) based electrodes, for supercapacitors, is often hampered by inadequate electrolyte accessibility within the pores of the AC, in addition to space charge capacitance (Csc), in series with the expected double-layer capacitance (Cdl). In this talk, we aim to investigate whether a capacitance increase would be facilitated through the plasma processing of AC.

It was aimed to determine whether plasma processing could contribute to enhanced capacitance and energy density of activated carbon electrode based electrochemical capacitors, through the formation of additional surface charges. While an increase of up to 35% of the gravimetric capacitance, along with ~ 20% decrease in resistance, was obtained through optimal plasma processing, increased plasma exposure yielded a drastic reduction (/increase) in the capacitance (/resistance). It was also found that the capacitance and resistance modulation was a sensitive function of sample processing as well as electrochemical testing procedure.

Considering the complexity of modeling realistic porous matrices, a metric to parameterize the reach of an electrolyte into the matrix will be posited. It will be discussed as to how an optimal plasma processing is necessary for enhanced capacitance ifor supercapacitor applications.