BYD's technology, not so much--they're better at manufacturing cars in degrees compared to Tesla, not an order of magnitude.
The magic is at CATL and friends. There is a Cambrian explosion of battery technology in China that doesn't get reported super well in the mainstream press.
Iron [1] and now sodium [2].
[1] https://en.m.wikipedia.org/wiki/Lithium_iron_phosphate_batte...
[2] https://www.electrive.com/2023/11/20/byd-huaihai-move-on-pla...
https://ev.com/news/byd-and-catl-set-to-introduce-ev-batteri...
Capacitors.
Huawei has already announced 600 kW DC fast chargers: https://asia.nikkei.com/Spotlight/Electric-cars-in-China/Chi...
https://www.drive.com.au/news/byd-to-introduce-new-second-ge...
They’re doing a lot of licensing to western companies.