“...pollution free...” might be a stretch...battery disposal seeems to be a significant issue.
I had a meeting with GM and DTE regarding car chargers in our town. The plan is to collect the old batteries, build them into some sort of super battery to store energy from wind and solar. Seems like a big stretch.
It will also be very interesting to see how well those batteries hold up over time. Notice how smartphone batteries tend to do great when you first buy them, but over time you seem to get less time out of each full charge. I think the longest I've ever kept the same battery is about a year, before getting it replaced. You also have to consider that those batteries for the cars will be out in weather, which couldn't be good for them.
Bottom line... There's a REASON we started using the internal combustion engine over 100 years ago. Steam, electricity, and even batteries were tried. The internal combustion was better. We as a nation need to just be more aggressive in producing our own oil.