A method to increase the specific energy of a double layer capacitor

Supercapacitors are energy storage systems capable to deliver high power rates compared to batteries. Nevertheless, supercapacitors which provide about hundred times higher power, are not able to store the same amount of energy of batteries (10-100 times lower) [1-2]. Therefore, their best use is in hybrid systems in combination with secondary batteries or fuel cells, in which supercapacitor provides the high power and the other system the necessary energy. Besides, supercapacitors have very long cycle-life (>500,000 cycles) and are maintenance-free [3], which make these devices able to be used in special applications, such as transmitters in remote places, where together with specific sensors and transmitting devices, may send long distance signals. In this case the energy for charging the devices is received by solar panels or wind turbines. Moreover, because many of primary energy suppliers (batteries, fuel cells) suffer the peak load during their normal operation and for this they must be oversized, the use of supercapacitors would permit to decrease their size causing a decrease of cost and an improvement of life and performance of the whole systems. Because current supercapacitors show energy density much lower than secondary rechargeable batteries, in this work we present a method to improve this property.