The company I work for made parts for the Fisker Karma, they were actually for the battery cooling system. So I have had some early exposure to Lithium Ion Batteries. BTW, if you don't know what a Superfund site is then google it. You are going to see this term used a lot in the coming years.
There is warehouse in New Jersey that is now a Superfund sight because 138 of those cars were parked there when hurricane Sandy hit. Submerging lithium ion batteries in salt water was a
very bad thing with those early lithium ion batteries.
Fact, high capacity lithium ion batteries cannot be transported by Air in the US. There is too much risk that a defect in one cell in the battery can cause it to blow up and set the entire battery pack on fire. The other issue is the energy capacity of these batteries. In some cases there is an energy equivalent to a couple of cases of Dynamite. While the energy release for Dynamite is extremely rapid the energy released by a lithium ion battery is also quite rapid and potentially deadly. As a result your "hot swap" dream will NEVER be realized. Note, think about it, if it were possible to be done safely NASCAR would already have a trial series going on for electric cars.
So go ahead and dream, nearly everyone was an idealist when they were young with great big dreams. Just realise that in about 20 years you'll be looking back and thinking "how could I be so dumb". I was part of the Vietnam Protest generation and we thought we could bring peace to the planet if we got people to talk to each other. You can see how well that turned out. What I learned is to to Trust No One and verify anything I've been told.
As for Green Energy, I'm all for it. However anything that involves a toxic material like Lithium is not "green", it's far from it and has the potential for polluting the sub surface water all over the world. So, what is truly "Green"? How about combusting Hydrogen and Oxygen. Zero Carbon compounds involved in that process and the
ONLY product of this particular combustion process is pure Water, fully drinkable and 100% pure. Yeah, we would be adding water vapor to the atmosphere but doing that might just make the Sahara Desert a green land where food could be produced while reducing the global mean temperature.
BTW there is a video on Youtube about the Green Sahara and it's well worth watching.
View: https://www.youtube.com/watch?v=nHNX1o7X6wUThe
Transition from a lush land to desert took about 200 years and it's amazing how quickly the climate can change due to factors well beyond the ability of the Human Race to do anything about them.