So far, ultracapacitors sweet spot has been applications that require quick burst of high power and can quickly be recharged.
Many applications capture the braking energy to replenish the ultracapacitorss (examples: buses, trucks, trains, and elevators). This sweet spot may be changing due to a recent nanotechnology discovery.
University of Texas at Austin, mechanical engineering professor Rod Ruoff has achieved a breakthrough in ultracapacitors by using "graphene". Ruoff says, “Graphene’s surface area of 2630 m2/gram (almost the area of a football field in about 1/500th of a pound of material) means that a greater number of positive or negative ions in the electrolyte can form a layer on the graphene sheets resulting in exceptional levels of stored charge.”
After about nine months of research with the new material, they have shown storage abilities similar to those of ultracapacitors already on the market, and they believe graphene's ultra thin structure will allow for sheets of the material to be stacked to increase energy storage and possibly double the current capacity of ultracapacitors. This would allow ultracapacitors to expand into many other renewable and clean energy application for both solar power and wind farms.
Graphene is a one atom thick structure of bonded carbon atoms that are densely packed in a honeycomb crystal lattice. It is best described as an atomic scale chicken wire of carbon atoms and their bonds. Graphene is strong enough to withstand diamond cutters and is one of the most expensive materials available today. Since it is currently so expensive, it will require some development before it is economical viable for mass production in ultracapacitors.
This research is exciting and maybe we will see the "new super battery" sooner than we think...
Readers have left 3 comments.
I'm glad to see some are looking at nano technology in a simpler, probably more workable form. Nanotubes are interesting but I don't see such fine structures being feasible to produce cheaply and in the quantities needed.
"Graphene’s surface area of 2630 m2/gram" - how is this possible?
The C-C bond length is 1.42 Angstroms. If one draws out a portion of the hexagonal lattice, it can be seen that each vertex is shared by 3 neighboring hexagons. One should do the geometry (for fun if nothing else) and this yields 2.60 square Angstroms per carbon atom. Then, 12 grams of carbon had 6.023 times 10 to the 23 power atoms. This is the simplest derivation of the surface area--accounting for both sides of the graphene sheet.