The details, which remained under wraps until now, come from people familiar with the situation who spoke to Bloomberg. According to the sources, the iPhone maker

Apple secretly collaborated with Chinese automaker BYD to develop long-range electric vehicle battery technology as part of its now-nixed Apple

Apple and BYD reportedly started to work together in 2017 and built a battery system using lithium iron phosphate cells. It’s claimed that Apple engineers working on the project had expertise in advanced battery packs and heat management, while BYD used its lithium iron phosphate cell skills and manufacturing prowess to make the partnership work.