Battery mining and manufacturing may not be toxic in the sense that you're describing them relative to exhaust emissions, but I would challenge you (in a friendly way, of course) to do some research into how the chemicals used in automobile batteries are extracted from the earth.
Two things to note here; usually strip mining is involved, which I think we should all agree is bad for the environment (certainly the immediate environment where the strip mining takes place), and also, China is big (as in BIG) into buying up mineral rights from poor or developing 3rd world countries, in many cases those in Africa and South America. Something tells me that China is not too concerned with treating the environment well in the process of exercising those mineral rights.
