Yes the graphene covered DVD put in a LightScribe DVD drive made a supercapacitor I'm sure that knowledge may someone help in making better batteries (yes I know a capacitor isn't a battery).
But a battery is a capacitor. Well, technically not, but they behave similarily, with the battery storing more energy per cubic centimeter than the capacitor, at the trade off of having a much higher internal resistance. Also I believe he meant data storage, since we have battery technologies which would work for this application, even though more juice is always a juicy prospect.
https://www.sciencemag.org/content/335/6074/1326.ful