A really cool development!

One can imagine eventually using batteries with simmilar mass specific energy storage density in electric cars, perhaps in plug in hybrid cars that use regenerative breaking.

If the energy storage density of batteries ever approaches that of the mass specific energy density of gasoline, fuels for prop driven aircraft, etc, we may yet see electric prop driven aircraft and electric helicoptors, although I won't hold my breath on such occuring any time soon. But if such vehicles could be developed, I would imagine that they could be made to operate very quietly compared to current prop driven aircraft.

Anyhow, a cell phone that needs recharging only 1 x/month; I will happily go for that.