I don't like to talk about such facts albeit undeniable, a we are always fighting for the car with one more bhp or which emits one less gram of CO2, and at the same time we don't have even the shadow of a reliable source for the emissions for the production of batteries, how much they pollute and so on. I'm pretty sure they have quite an impact on the environment, and I'm not saying it isn't something to consider, just with the right sources and figures.
It could even come out that batteries are more toxic than nuclear wastes, I don't care about the outcome, what I care is that it's going to be technical and reliable.