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Laser writer makes graphene supercapacitors


A routine laser-writing technique has been used to create sheets of graphene on the surface of a DVD. The work was done by researchers in the US, who then joined the sheets together to make electrochemical capacitors (or supercapacitors). The devices can store as much energy as a conventional battery but can be charged 100–1000 times faster. According to the researchers, the capacitors are completely flexible and robust, which makes them ideal energy-storage systems for flexible and portable electronics.


Electrochemical capacitors – also known as supercapacitors or electric double-layer capacitors – can store much more electrical charge than standard capacitors. This is thanks to the double layer formed at an electrolyte–electrode interface when voltage is applied to the device. Although promising energy-storage materials, supercapacitors still lag behind traditional batteries in terms of energy densities: 4–5 Wh/kg and 10–150 Wh/kg, respectively. They do, however, have a much longer shelf – and cycle life than batteries and can deliver large amounts of energy much more quickly.


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Lees verder: http://physicsworld.com/cws/article/news/48991


Bron: Physicsworld