The battery is sourced from Ganfeng Lithium, CATL, Panasonic, and/or LG Chemical. The majority actually comes from CATL. The world’s leading EV battery manufacturer. Various automakers work with them. The cells arrive at the automakers manufacturing and all they do is pack it into a case. The statement they have leading battery tech is disingenuous. No matter which automaker you look at, they’re using the same cells from the same sources.
Lastly, Tesla isn’t ahead. China is. It’s why automakers are going to them. Credit where it’s due, Tesla did push for EV adoption outside of China. But that’s about it.