Actually, Li is a very common mineral in various forms and it is...

Actually, Li is a very common mineral in various forms and it is plentiful on a worldwide basis. There are proven processes to extract it from sea water in commercial quantities. It can even be extracted from oil and gas wastewater brine, although that is likely to become a diminshing source. Spodumene is currently the favoured form of mineral because it is cheaper to produce battery grade Li2Co3 from. Even so, Lepidico has a new process to do that from other Li ores. Hence, I doubt Li will be declared a strategic material by the major consumers, although perhaps the refined product will be.
The DRC can completely ban the export of Li and the world will yawn. China is currently the major producer, if I remember correctly. Cobalt ore is different.