Super Capacitors - A Breakthrough in Energy Storage

Capacitors have been with us for a long time. The invention of the capacitor has been, historically, somewhat controversial. In Germany, scientist Ewald Georg Von Kleist built a capacitor in 1745 according to historical records and, in Holland, a University of Leyden professor, Pieter van Musschenbroek, invented a similar device called a Leyden jar a few months later. A Leyden jar was what Benjamin Franklin used in his famous kite experiment. Franklin later improved on the jar and discovered a way to use a flat piece of glass to do the same thing, called a flat capacitor, leading to what we have today. Michael Faraday was the first to put the capacitor to practical use.

Capacitors are used to store and discharge energy in an electrical circuit. The are also used as filters that purify and stabilize electrical energy, cutting down on noise and unwanted signals in the circuit. They can be built into a circuit to charge and discharge at a set rate of time which is useful for electronic control.

You could say a lot has changed and at the same time very little has changed with the technological advancement of the capacitor. Most advancements have been in reliability, compactness, electrical characteristics, and other factors due to use of different materials and chemicals.

Super capacitors, also called ultra or double layer capacitors, store electrical energy by the separation of positive and negative charges and it builds up fast due to the large surface area. They can also discharge quickly. This makes them very useful in many applications such as regenerative braking systems, electric vehicle motors, cell phone and laptop battery recharging, or most any device using conventional battery technology.

The development of hybrid combination of the battery and super capacitor is what makes this a new and promising technology. A battery can hold much more power than the super capacitor but has a lower discharge rate. Putting them together gives you the best of both worlds. Improvements on the design are advancing rapidly, especially in the reduction of the size of the capacitor. Other advantages are long-life, biodegradability, and low impedance.

Super capacitors are the answer scientists have been searching for to advance battery technology. Previously, manufactures of portable electronic devices and electric vehicles were at a standstill to let battery technology catch up with theirs. Scientist at Stanford University have just discovered a new battery technology that promises to move us even farther into the future. They are working on bringing us lithium-sulfur batteries that are safer than the conventional lithium-ion battery and have 10 times the energy storage. The future of battery powered devices is looking good.

Marshall Brain and Charles W. Bryant, "How Capacitors Work." How Stuff Works
"Super Capacitors." Supercapacitors.org
"Optixtal Introduces the World's First Ultra-Thin Supercapacitor." Optixtal.com
Brian Westenhaus, "Lithium Sulphur Battery Progress." New Energy and Fuel