Tesla wants to speed up the adoption of electric transportation. It has tried this by developing innovative vehicles using Lithium Ion batteries and it has improved on that technology in house with their own battery form factor, new tabless batteries, reduced Cobalt use. But it seems this strategy is not moving fast enough.
Now it seems to be rethinking its battery chemistry, and it seems the option Zinc-Air is considered. Zinc is a metal that rusts really fast, so it develops a coating of zinc oxide on its surface, that stops further corrosion. This is also the case with Lithium and Alumium. Zinc is super abundant and cheap in the world. The battery pack can ‘breath’ oxygen from the ouside air, and this means the design of the battery pack will be different, and other things as I will explain below.
Zinc-Air batteries are so called primary batteries though, you can’t recharge them. That means that if you use them your car turns into a brick when they are used up. The funny thing is that Tesla has been looking at and revisiting a solution to that drawback : The semi-automatic battery swap.
Tesla has apparently kept battery swappability alive, and it is working on a new type of swap station. That means it could eventually swap depleted Zinc-Air batteries out for recycling. Even though the weight of Zinc-Air batteries is higher, the swappability will mean a smaller battery can suffice.
Zn-air battery has received the attention because besides of having a higher theoretical energy density (1.3 kWh kg−1) compare to the current energy storage systems , zinc is abundant in nature, environmentally safe, and can be handled safely in oxygen and humid atmosphere. (source)
This may be one of the secrets revealed on the upcoming Battery Day on september 22th 2020 (click to visit the livestream). For stationary storage Zinc-Air is not usefull, because one would have to replace batteries all the time. Maybe a design can be developed to make Zn-Air rechargeable, but one of the reasons the energy density is high is because Oxygen -really- likes Zinc!
So will we see SEMI trucks run 80 miles and swap out at automatic stations? Some think Tesla should! It would certainly make the process cheaper and thus more easily accepted!