I'm still kind of shocked lead acid is faring so poorly when it comes to grid storage. One of the oldest (the oldest?) battery chemistries, well understood, really cheap, mostly safe, simple, durable, serviceable, recyclable. (sidenote, submarine warfare was, for decades, powered by lead acid)

It's chief disadvantages are low power density and low power to weight ratio, neither of which matter for grid storage.

It just seems to have all the hallmarks of traditional industrial solutions. But, of course, lithium ion has the same advantage ubiquitous silicon semiconductors have- massive, massive economies of scale and endless R&D dollars.

Bankruptcy doesn't always mean going out of business. And the IP is still probably good, and likely going to be liquidated and sold on to someone else (who will hopefully start a new business with the tech).

That is unfortunate, but considering the opportunity presented by the need for grid-level energy storage for renewables or even by the need for domestic energy storage for solar as well as the apparent availability of materials it could be an attractive area for innovation.