As I12Ride notes, the whole idea of "zero emissions" is a false issue ... lifetime environmental impact is the real measure, and even if the battery is solar-charged, making solar cells is quite impactful ... and making batteries, from mining to manufacture, is extremely destructive ... and as far as what to do with the old batteries .... yeah, that's an issue.
And if you charge the bike at home ... . well, 25% nuclear, and about 70 % diesel or coal-generated electricity in most parts of the country. Where is the "zero emissions" in that?
I am fine with electric-assist bikes, electric scooters, electric mini-motorcycles or whatever ... but don't lie about them. it is insulting.
Between Mr Newleaf and I12 I'd say the issue is finished.