Environmental economics - how green are electric vehicles?

How green are electric vehicles, from construction to disposing of these cars. The cobalt-lithium batteries aren't environmentally-friendly, but the cars themselves need charging - which means that the shift away from coal in the UK is a good thing.

And when you are getting rid of these cars, what are the envronmental costs? There about the same as a conventional petrol car, and over time they're going to become cheaper, not just in an environmental sense.