I haven't read the follow up comments yet, but I was struck by what you said about no comments about EV applications.

Metal-air batteries are not new, just getting more and more refined over time.  The ultimate "Air Battery" at one time was prognosticated to be the Aluminum-Air Battery, but research has also been done and continues with development of Vanadium-Air Batteries, Lithium-Air Batteries, Magnesium-Air Batteries and Zinc-Air Batteries among others. The Iron-Air Battery is just one more rendition of the concept, if I understand it correctly.  All of these "Air Batteries" have a significant multiple of energy density over and above the present state of Lithium Ion Batteries, so of course there is speculation that they will ultimately supplant the Lithium Ion Battery, but there are valid reasons why commercial scale Air Batteries have not done so as of this date in time, significant technical hurdles to overcome.

A Stanford student submitted this short note about the challenges of Metal-Air Batteries back in 2016:

Metal-Air Batteries: Promises and Challenges (stanford.edu)

An eye opening statement about "Air-Metal Batteries" is included in an old, 2013 article about Tesla's interest in Metal-Air Batteries:  "As battery guru Venkat Srinivasan noted on GigaOM a couple years back: the theoretical energy density of a metal air battery is comparable to gasoline." 

 Wow!  Comparable to gasoline energy density, no wonder Tesla has been interested.  See the link:

What’s a metal air battery and why is Tesla interested in it? – Gigaom

A 2018 article about research on Aluminum-Air Batteries has some interesting comments:

New Metal-Air Battery Design Offers a Potential Boost to Electric Vehicles - Tech Briefs

British engineer Trevor Jackson claims that if you replaced a Tesla Model S lithium-ion battery with one of his aluminum-air batteries of the same size, range would increase from 370 miles to 1,500 miles:

Aluminum-air battery creator says long-range tech will be in cars soon (autoblog.com)

OK, my "around the barn" style of answering Bodysurfer's point ( " From what I read I don't see anything about EV batteries, but more about power stations." ) is about to address that issue:  put quite simply, the Iron-Air battery is too heavy to be practical for EV application, however ( and this is the reason for the around the barn journey ) other types of Metal-Air Batteries might indeed be applicable for EV utilization.. so stay tuned!

A four-year-old startup ( Form Energy Inc. ) says it has built an inexpensive battery that can discharge power for days using one of the most common elements on Earth: iron.

Form Energy Inc.’s batteries are far too heavy for electric cars.

Startup Claims Breakthrough in Long-Duration Batteries - WSJ

Okiedo