Originally Posted by
tpreitzel
I'll guarantee you that lead acid isn't going away as the infrastructure is simply gigantic and well established worldwide. Lithium reserves are limited so we already know that lithium based chemistry is simply transitional to another type of chemistry, e.g. zinc-air.
This is something that a lot of people in the ebikes and EV supporters, as well as the nay-sayers, fail to think about a lot. Lead may be toxic but so is lithium. The infrastructure for lead based batteries is very well established and thus much more eco-friendly simply by the fact that it is easy to recycle lead batteries.
Lithium is also a rare-earth metal and therefore not going to get cheaper as it is more and more widely adopted. The last thing the world needs is another resource crunch like with oil reserves/production.
I continue to be hopeful for lead technologies and the zinc based compounds sound like a good idea as well. I'm pretty sure Zinc is about as non-toxic as you can hope for. Zinc technology isn't coming real fast though, secondary Zinc batteries are horribly inefficient to re-charge... right now.
As for the carbon-nanotubes, I think they are an excellent potential storage medium but I worry about the potential for catastrophic failure for a cell based on these. The available discharge rate for nanotubes is more similar to capacitors than batteries. Of course that changes as lead based battery energy density and current delivery issues are solved. Seeing a capacitor explode and seeing an old lead-acid battery explode are pretty scary when you consider packing more and more amp-hours into a motor vehicle.
When the energy density and re-charging issues are solved, there will be a safety issues to consider. As with safety mechanisms at gas stations and collision safety designs in gas tanks, high amperage charging stations at home or at pumping stations and battery cell arrays in vehicles will have to be carefully designed.