Yes definitely not thermocouples which are only around 6% to 7% efficient , but these new Powerchips of which they won't release the full details about efficiency, etc. Once these technologies are more efficient than a IC engine it will make no sense to have IC engines any more. Diesel locomotives around the world already run on transmissionless IC - electric systems, all their traction motors are AC motors, the diesel IC engine is purely a generator. Only very old diesel locomotives use their diesel engines for direct motion.
Even thermocouples are there already, efficiencies over 20%
https://www.extremetech.com/extreme/...ium-production