Workers are seen at the production line of lithium-ion batteries for electric vehicles (EV) at a factory in Huzhou, Zhejiang province, China August 28, 2018. REUTERS/Stringer Acquire Licensing RightsMADRID, Sept 17 (Reuters) - The European Union could become as dependent on China for lithium-ion batteries and fuel cells by 2030 as it was on Russia for energy before the war in Ukraine unless it takes strong measures, a paper prepared for EU leaders said.The document, obtained by Reuters, will be the basis of discussions on Europe's economic security during a...