I would think any dry cell would have this as a problem? If you stuff a kWh into a box and get it back out without adding anything, there is a kWh in that box,

I would think any dry cell would have this as a problem? If you stuff a kWh into a box and get it back out without adding anything, there is a kWh in that box, and I think all these sorts of reactions proceed faster at higher temperatures, so wouldn't runaway always be a possibility?