10-01-2011, 04:59 PM
ULTRACAPACITORS.ppt (Size: 2.49 MB / Downloads: 366)
Traditional capacitors
Two electrodes, or plates separated by a dielectric
Capacitor’s energy stored in electric field
CONSTRUCTION
Double-layer technology
Electrodes: Activated carbon (carbon cloth, carbon black, particulate from SiC )
Electrolyte: KOH, organic solutions, sulfuric acid
Limitations of Activated Carbon
Non uniform porosity:
Multiple time constant
Much of the surface area is not utilized
Limited ion mobility
Limited conductivity due to amorphous nature of activated carbon
Bonding limitation due to
Electrode junction has high resistance
FEATURES
Energy storage device with excellent power capabilities ,high reliability
Long life -1 million charging cycles
High capacitance –about 3000F
No chemical reaction
Improved safety
Enhance efficiency
Optimize system size and cost