Cost is a pretty big reason. Tesla has made somewhere around one and a half million cars. If you want to make a billion cars, that's a whole different situati

Cost is a pretty big reason. Tesla has made somewhere around one and a half million cars. If you want to make a billion cars, that's a whole different situation. the resources needed to make the batteries could become pretty severe bottlenecks. I think that's something that's often missed in EV discussions that focus on range and who has the best 0-60 time and so on: luxury car features are nice, but in the end what matters more is who can actually make the cheapest good-enough battery at the highest volume, because that's what's going to be in most of the world's cars. Wherever those batteries are made could basically be what Saudi Arabia was to the era of gas-powered vehicles. (Though to be fair you can build a battery factory almost anywhere, whereas oil is something you either have in abundance or you don't.) Not sure what the inputs are to these sodium ion batteries, but most lithium ion batteries require cobalt, nickel, and lithium. Lithium iron phosphate has an advantage that it doesn't require cobalt or nickel.