An interesting development for the Leaf - our friends at EV's Enhanced in New Zealand have been developing a completely after market replacement battery for the Leaf which includes a fully active liquid cooling system - and not just using heat exchangers as is usually done, the cells are actually directly bathed in the (non conductive) cooling fluid....
Will there be enough of a market for it as Leaf's age ? Who knows, but depending on the cost it would beat replacing an old degraded or failed battery with another one of the same design with the same lack of cooling that will just suffer from the same fate and have the same rapid charging limitations...