Hacker News new | past | comments | ask | show | jobs | submit login

Her invention is certainly probable and represents a significant achievement -- extremely impressive for a high school student -- but it is not "revolutionary." Her claimed specific energy is 20 Wh/kg, comparable to the state-of-the-art in nanostructured supercapacitors (not always graphene!) which a quick Google shows to be around 31 Wh/kg:

http://pubs.acs.org/doi/abs/10.1021/nl2023433

So her supercapacitor is roughly on par with similar nanostructured supercapacitors being developed. I must stress that the highest specific energy does not always mean the best technology, but practical/fabrication considerations can lead to different things making sense for different applications, in particular you have to watch out for the nasty tendency of some capacitors to short-circuit, which at supercapacitor energies means "kaboom!".

That last bit is why expensive tantalum capacitors are often preferred over cheaper fabrications with higher specific energy: tantalum is safe and reliable, which matters a lot.

edit: I should also point out that neither her supercapacitor nor other current nanostructured supercapacitor electrodes achieves an energy density on par with a cellphone battery. The specific energy of a lithium-ion polymer battery used in cellphones is roughly 150-200 Wh/kg: nearly ten times as much as this girl's claim!




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: