Samsung SDI, the battery business arm of Samsung Group, said Wednesday that it had inked a supply deal of its lithium-ion batteries and battery management systems with Duke Energy, the largest electric power company in the U.S. The supply deal is the latest of SDI's moves to increase its presence in the global storage system industry. SDI made deals with U.S. energy solution service provider GCN, Japanese capacitor maker Nichicon and electronics manufacturer Sharp during recent years to provide batteries and energy storage systems.