A Tesla Megapack battery at the Harmony Energy Ltd. and Fotowatio Renewable Ventures BV battery energy storage project near Burgess Hill, England, May 11, 2021.Chris Ratcliffe | Bloomberg | Getty ImagesTesla is expanding ties with South Korea's LG Energy Solution, striking a deal to buy $4.3 billion worth of battery cells that will be made in Lansing, Michigan for use in its energy storage systems.The plant was formerly developed for a joint venture between LG and General Motors before the autom...