The power density of batteries sucks compared to liquid fuels, and it always will. I don't care if you double or quadruple their efficiency. Can't touch liquids. I have a Prius myself, and I do love the way it does regenerative breaking. I would dearly love it if I could use a fuel in it that was made from atmospheric CO2 or crop waste with solar power, so it was totally carbon neutral. And then used a fuel cell instead of an IC engine.
It does no good to charge really great batteries with fossil fuel powered electricity. And of course that 'million mile battery" means you can charge them and discharge them for a million miles before you have to recycle them. It does not mean you can charge them once and drive a million miles.
God sent Trump.......because God was out of locusts.