I get what you mean, but...how many things have we thought (as humans) over the ages that would never be overcome, and...science found a way.
I just keep in mind we don’t know everything, and who knows, if they figure out room temperature superconductors or things like that, or some other mode of generating electricity, anything is possible.
That is the optimist in me...:)
Of all of the things we figured out as a species, none of them violated any of the laws of physics. Plus keep in mind that a battery consists of an electron acceptor and an electron donor in clos proximity (or in other terms fuel and an oxidizer in close proximity). Now considering how hard it is to put our a fire in one of the current type lithium cells that have only 1/50 of the energy density of gasoline just think what will happen when if the energy density gets increase by a factor of 5 (something I think is unlikely to ever happen) you now have an incendiary bomb waiting to go off. Gasoline is relatively safe because the fuel is stored separately from the air and only mixed in the engine. If you want an analogy to a really high energy density battery think ammonium nitrate mixed with diesel fuel.