[semi-extrinsic]

Mercedes is already doing CO2, and the next-gen EV platforms are going that route as well, from what I hear. The high pressure of CO2 systems mean that they're very compact, and thus much easier to integrate with battery pack temperature regulation, AFAICT.

[jabl]

That's good to hear.

I think the interest for EVs might be due to CO2 systems being capable of working as heat pumps as well, producing hot air. Otherwise you'd waste a lot of electricity in cold climates.

[semi-extrinsic]

Exactly this, both that they're able to heat the interior of the car, but also that they can play the role of battery cooling system (just heat a small radiator instead of inside of car).