They're one step ahead of the vaporware stuff you normally read about in that they are already operating at a scale worth noticing (no long lab level power but 100's of KW) and they are about to scale up to 5MW which will be a very important proof point if it can be done economically and reliably enough.
I really want them to succeed for the sake of the planet, but it's another "revolutionary new battery just five years away" story.