Running water cooling in the pack seems like a much easier issue than creating faster charging chemistry though.
Easy, at a expense of weight and volume.
Detachable/external cooling, maybe? You don't need to dissipate that much heat during normal operation.
That's just called Mechanical Engineering. All machines involve compromises. An internal combustion engine needs oodles of these kinds of compromises. It's idiotic thermal efficiency itself is a big expense if you think about it.
Yes, I'd like to see further efficient developing.
All current EVs have liquid cooled batteries already.