That's a fair point but nevertheless what the article meant by lack of need for cooling is twofold. The ability for the aluminum ion battery pack to function i

That's a fair point but nevertheless what the article meant by lack of need for cooling is twofold. The ability for the aluminum ion battery pack to function in a wider temperature range potentially does away with a heating system that is otherwise needed to help li-ion battery packs to function better (or even avoid early degradation) from a cold start. The implied lack of a need for a cooling system for the battery means the battery can function as a thermal mass, as you alluded, and a lower rate of circulation and total mass of coolant is necessary. That's on top of a simplified channel system that runs only through the motors, alternator, electronics that lie next to heat generating parts, etc.