[RightWingRabble]

Agreed. One of the reasons Li-ion (Lithium Cobalt Oxide) batteries are so expensive is the extensive quality controls that have to be performed on it. If you put 100 cells in a car and even 1% of those cells are faulty, your car catches fire. The worst that happens with LiFePO4 is the internal goo bubbles out of the battery and smells bad.

AFAICT, Tesla uses Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2) aka "NCA". It's safer than Cobalt, but not as safe as Iron.

[Gravityloss]

I understand cobalt is a big cost issue and is not plentiful.