Exxon Mobil said Monday it is starting to drill for lithium in Arkansas and aims to become a major U.S. supplier for makers of electric-vehicle batteries by 2030.  

The Texas-based oil company’s entrance into the lithium business, first reported by The Wall Street Journal in May, is an effort to reposition itself long-term for the advent of EVs and electrification in the transportation sector, which it dominated for decades as one of the world’s largest fuel makers. Lithium is a key ingredient in making batteries for EVs, cellphones and laptops.