What Is A Supercapacitor?
A supercapacitor (SC) (also called a supercap, ultracapacitor or Goldcap) is a high-capacity capacitor with capacitance values much higher than other capacitors (but lower voltage limits) that bridge the gap between electrolytic capacitors and rechargeable batteries. They typically store 10 to 100 times more energy per unit volume or mass than electrolytic capacitors, can accept and deliver charge much faster than batteries, and tolerate many more charge and discharge cycles than rechargeable batteries. Super capacitors merged with batteries (hybrid battery) will become the new super battery. Just about everything that is now powered by batteries will be improved by this much better energy supply. They can be made in most any size, from postage stamp to hybrid car battery pack. Their light weight and low cost make them attractive for most portable electronics and phones, as well as aircraft and automobiles.
Uses For Supercapacitors
Supercapacitors can be used in a wide range of applications. One is storing energy for dynamic braking systems called KERS (Kinetic Energy Recovery System) which is used in the automotive industry. They are also exploited for supporting low supply current for memory backup in SRAM (Static Random-Access Memory), a part of a computer’s RAM (Random-Access Memory).
Advantages
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Virtually unlimited life cycle – cycles millions of time -10 to 12 year life
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Low impedance
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Charges in seconds
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No danger of overcharge
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Very high rates of charge and discharge
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High cycle efficiency (95% or more)
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Super capacitors and ultra capacitors are relatively expensive in terms of cost per watt
Disadvantages
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Linear discharge voltage prevents use of the full energy spectrum
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Low energy density – typically holds one-fifth to one-tenth the energy of an electrochemical battery
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Cells have low voltages – serial connections are needed to obtain higher voltages. Voltage balancing is required if more than three capacitors are connected in series
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High self-discharge – the rate is considerably higher than that of an electrochemical battery.
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Requires sophisticated electronic control and switching equipment
