SEOUL, April 20 : South Korean battery maker Samsung SDI said on Monday it has signed a multi-year agreement with Mercedes-Benz to supply batteries for electric vehicles, marking its first EV battery supply deal with the automaker. The batteries will feature high-nickel NCM (nickel, cobalt, and manganese) chemistry, powering Mercedes-Benz's next generation EVs, Samsung SDI said in a statement. Mercedes-Benz planned to use the batteries in future compact and mid-size electric SUVs and coupe