The strategic importance of lithium is likely to have played a major role in the European Union’s blockbuster deal with Brazil, Argentina and three other South American countries, analysts say. After 25 years of talks, the EU and five Mercosur countries (an alliance which includes Paraguay, Uruguay and, newly, Bolivia) reached a highly anticipated trade agreement on Dec. 6. If ratified by the 27-nation bloc, the EU- Mercosur partnership will create one of the world’s biggest free trade...