Activated carbon is a primary component in ultracapacitors, an emerging alternative to traditional battery technologies. Ultracapacitors are synonymous with supercapacitors and electric double-layer capacitors ("EDLC"). Activated carbon ultracapacitors offer faster charging and discharging of power, better cycle life, and greater reliability than traditional batteries.
Ultracapacitors have two metal plate electrodes coated with activated carbon. Virtually all ultracapacitor manufacturers use activated carbon which must have a particularly high porosity and a low level of impurities such as that manufactured by Millennium Carbon. These plates are immersed in an electrolyte solution. One carbon-coated electrode is positive, and the other is negative. When a voltage is applied across the electrodes, a charge separation builds as positive and negative ions from the electrolyte accumulate on the surface of each carbon-coated plate. This charge separation creates a useful electric field between the electrodes.
Due to their many benefits, ultracapacitors are currently being utilized in thousands of applications, and the market for ultra capacitors continues to accelerate.
"Ultracapacitors have much lower energy density than batteries, and their low energy density is in most cases the factor that determines the feasibility of their use in a particular high power application."