Tesla sold 70,847 China-made vehicles in December, the highest monthly rate since it started manufacturing in Shanghai in 2019, China Passenger Car Association data showed.

Tesla is working with suppliers, including partner Panasonic, on a bigger cylindrical battery cell to increase efficiency and reduct cost. In fact, Tesla is already making some of the 4680 cells on its own.

J.B. Straubel's broader goal is to move a huge chunk of the battery-component industry from Asia to the U.S., Bloomberg reported.