[tinganho]

And what's the capacity?

[kazinator]

This article is more about the service life of the battery not about charge capacity. (Though, of course, charge capacity would good to know: how does this compare to a Li-Ion of comparable weight or space.)

I imagine that the prototypes they are working with don't have great capacity. For that you need clever manufacturing to miniaturize the storage elements and pack a lot of them into a small space.