“All of us here, we are ready to lose our lives,” says Serbian farmer Zlatko Kokanović. The 48-year-old does not want a lithium mine in his backyard and he will do anything he can to stop it from opening. “They can shoot. That is the only way they can open the mine.” At stake is a lush farming valley in western Serbia that holds one of Europe’s richest deposits of lithium, a precious metal that is used to make batteries for electric cars and is crucial for the global transition to green energy. Whether there should be a mine in the valley or not has become one of the most contentious issues in…