It's probably the editor's fault for writing a shoddy heading, but I don't see a scientific accident anywhere in the text, or in the original paper. But it is quite cool, the first time I've seen a capacitor with anywhere near the energy density of a battery - although if I understand power density right, I am not sure how useful this will be for most electronics, since it looks like it discharges fairly quickly and at a high voltage. But maybe I'm wrong about that.
But I agree, it will be some time before this becomes useful. For one thing, to give a justification to turning this into a commercial technology it would have to exhibit greater energy density than Lithium batteries do today, and more importantly it would have to scale safely. As shown by the Dreamliner fiasco, the energy density of existing batteries is high enough to be dangerous (I mean, it is almost as dense as some explosives) so to scale to a higher density the material has to be easy to control otherwise we will be having more spontaneous phone combustion. The scaling and the testing of these batteries is going to take a few years, obviously, but there is always a chance it won't lead anywhere useful (such is the lot of the researcher).