General Motors GM -3.42%▼ and Ford are doing what they can to reassure investors they will have enough electric-vehicle batteries to take on Tesla in the coming years. True security of supply, though, is shaping up to be a long-term challenge. GM announced two deals alongside weak second-quarter results on Tuesday. One was with Korean chemicals giant LG Chem for five million EVs’ worth of so-called cathode active materials (CAM), which make up about 40% of the cost of battery cells. The other was with U.S. miner Livent for a key input, lithium hydroxide. Ford made a similar raft of supply agreements public last week. The partnerships are a response to investor concerns that EV model launches and ambitious sales targets are of little use if companies can’t get the materials needed to power them. First GM and Ford committed billions of dollars to battery factories. Now they are […]