North America is now the growth leader for new battery factories
Most batteries are custom made for their end clients.  A Tesla for instance does not have 10mil AAs squeezed into the chaisse, it has model specific weird shapes with proprietary connectors etc.  Batteries do not require high tech or high cost manufacturing plants either (like say leading edge microchips).  Similarly most applications for batteries (most of manufacturing really) uses Just In Time inventory management.  Batteries are (saly still) bulky and quite heavy, so you don't really want to ship them about, especially not as (fast) air freight.<p>So it makes sense that most regions (or even individual countries) will ultimately end up making their own, locally.