There's plenty of stored energy in a slab of solid steel, but that doesn't make it remotely dangerous. What makes lithium-batteries dangerous is the thermal runaway, enabled by the liquid capacitor.
We got pretty good at making it acceptably safe to drive around at 80mph with tanks of volatile liquid fuel right behind or under us. We’ll get good at this too. Lithium batteries are already surprisingly safe for what they are.
There's plenty of stored energy in a slab of solid steel, but that doesn't make it remotely dangerous. What makes lithium-batteries dangerous is the thermal runaway, enabled by the liquid capacitor.