Can you say more about 'battery disposal' ? As far as I can tell the batteries in the Tesla are largely recyclable (for example most, if not all of the material in that batteries can be recovered out of 'dead' batteries).
That means that putting the battery pack from an 85 kwh Model S in a landfill is equivalent to putting a stack of over 300 $20 bills in a landfill.
(He was actually trying to make a point about how cheap battery packs might be to buy new in the future, with more efficient techniques for turning the raw materials into battery packs.)