Lithium and lithium compounds can be toxic: https://en.wikipedia.org/wiki/Lithium#Precautions https://en.wikipedia.org/wiki/Lithium#Precautions The batteries

Lithium and lithium compounds can be toxic: https://en.wikipedia.org/wiki/Lithium#Precautions https://en.wikipedia.org/wiki/Lithium#Precautions The batteries envisioned by Ambri would be enormous, shipping-container-sized things sitting (stationary) in the same place (e.g. electrical substations) for decades. If one cracked open, it would be a bad day at the plant, but nothing like a nuclear reactor meltdown. It could probably be back to normal in days or weeks. The fact that the Ambri batteries are made using abundant materials means that those very materials are already present, in vast quantities, in the environment.