I'm super confused...a lot of people say that this battery works only between 10-40C but I remember a couple weeks ago and there was a Stanford article on how t

I'm super confused...a lot of people say that this battery works only between 10-40C but I remember a couple weeks ago and there was a Stanford article on how they made a mebrane operate at room and high (200C). Is the 10-40C a limit on Vanadium or the membrane used?! If it is the membrane, does that mean the article is click bait?!