Why did Salt Lake Company sell Michelle Lithium Industry?

Two patents are about to expire. Even though technical cooperation is still guaranteed by agreement, other shareholders of Michelle Lithium Industry have to face another reality: the two patents originally invested by Qinghai Fozhao and Qinghai Weili are about to expire (the patent protection period is 20 years, from 20 10 to 10). There is no doubt that BYD has a certain foundation in the field of new energy vehicles and lithium batteries. Does it have the advantages of upstream technology such as lithium resource extraction and processing? What are the advantages of BYD in Salt Lake? As of press time, we have not received a reply from Salt Lake.