How are batteries cooled in passenger aircraft?
As far as I can tell, current aviation lithium batteries do not use active cooling.

I know the True Blue Power TB17 (Robinson R44 &amp; R66, Bell 505 Jet Ranger X) and TB44 (Cessna Caravan, DHC-6, DHC-8) do not require active cooling.

I haven't seen any easily accessible info on the Saft batteries for the A350.