[arantius]

> ... batteries that use flat cells (called "Pouch Batteries") ...

They are but I think the more official/rigorous term is "prismatic cell".

https://www.google.com/search?q=prismatic+cell

(As opposed to cylindrical like 18650 et. al.)

[notjulianjaynes]

And prismatic cells are used in a large majority of electric vehicles, Tesla excluded.