Abstract:
Activated carbon powders (ACP) were produced from the KOH treated pre-carbonized rubber wood sawdust.
Different conductive materials (graphite, carbon black and carbon nanotubes (CNTs)) were added with a binder
(polivinylidene fluoride (PVDF)) into ACP to improve the supercapacitive performance of the activated carbon (AC)
electrodes. Symmetric supercapacitor cells, fabricated using these AC electrodes and 1 molar H2SO4 electrolyte, were
analyzed using a standard electrochemical impedance spectroscopy technique. The addition of graphite, carbon black
and CNTs was found effective in reducing the cell resistance from 165 to 68, 23 and 49 Ohm respectively, and
increasing the specific capacitance of the AC electrodes from 3 to 7, 17, 32 F g-1 respectively. Since the addition of
CNTs can produce the highest specific capacitance, CNTs were chosen as a conductive material to produce AC
composite electrodes that were added with 2.5 %, 5 % and 10 % (by weight) electro-active material namely ruthenium
oxide; PVDF binder and CNTs contents were kept at 5 % by weight in each AC composite produced. The highest
specific capacitance of the cells obtained in this study was 86 F g-1, i.e. for the cell with the resistance of 15 Ohm and
composite electrode consists of 5 % ruthenium oxide.
