Many analysts and industry officials expected Musk to unveil battery improvements at the widely-anticipated event, extending the automaker’s lead over General Motors , Volkswagen and other rivals. In a tweet ahead of the event scheduled for Tuesday, Musk said: “This affects long-term production, especially Semi, Cybertruck & Roadster, but what we announce will not reach serious high-volume production until 2022.” Musk also said Tesla intends to increase battery cell purchases from suppliers Panasonic , South Korea’s LG Chem and China’s CATL , and possibly with other partners as well.