Since the first series-produced plug-in electric cars appeared on the market over 10-years ago, there was not much lithium-ion battery cell manufacturing capacity in the U.S. Producing battery packs in volume was also a completely new thing.
As we can see in the latest U.S. DOE’s Office of Energy Efficiency & Renewable Energy's report, based on Argonne National Laboratory's research, the situation has changed since then.
Initially, most of the battery cells for plug-ins in the U.S. were supplied from Japan or South Korea. Things changed a lot in 2018 - thanks to the volume sales of the Tesla Model 3, equipped with batteries produced at the Tesla Gigafactory in Nevada.
Over the last three years, 70% of battery cells in plug-in electric cars were produced domestically in the U.S., and this number is expected to increase significantly with multiple very large investments in new battery gigafactories (including GM-LG Chem and Ford-SK Innovation joint ventures).
In the case of battery packs, things were different, as vehicle manufacturers right from the start tried to build their own packs, or even modules. We can see foreign packs basically only in imported cars. Over the last three years, the share of domestically produced packs amounted 87%.
We guess that both numbers will go beyond 90% and 95% later this decade.
Source: Yan Zhou, David Gohlke, Luke Rush, Jarod Kelly, and Qiang Dai (2021) Lithium-Ion Battery Supply Chain for E-Drive Vehicles in the United States: 2010–2020. Argonne National Laboratory ANL/ESD-21/3. Figure ES-1.
An important thing to note is that the electricity to run the electric cars is also produced domestically, which makes the EV industry less reliant on external factors.
The EV industry is different from the ICE industry, but overall it's a good thing not only from an environmental perspective but also economically.