That is neat. Not only is it another feat of miniaturisation for batteries, it also (at least, seems this way to me) makes it easier to make batteries in weird shapes. For instance, a mobile phone could have a "sheet" of battery covering the whole inside back of the case, which could improve the balance and lightness factors.

I found this fascinating: "You can stack one sheet on top of another to boost the power output..." So remind me - what's the word "battery" mean?

"The device can function in temperatures of 300 degrees Fahrenheit and down to 100 below zero..." - WOW. Just wow. If it can maintain full storage capacity at that range of operating temperatures, that's doing pretty well.

Pretty impressive. Not all that unexpected, though, as advances like this do keep happening; but, congrats to the researchers. This looks good.