The smaller batteries, I think, are standard lithium batteries. If you were to open up a lithum powerpack, you’d see these batteries that are shaped like AA batteries, but they are bigger. That’s the standard battery that is used in electronic devices. They are called 18650’s.
https://en.wikipedia.org/wiki/18650_battery
I was referring to energy density in smaller cells.
Smaller as in smaller than EV cells.