DETROIT—General Motors says it’s looking for a site to build a second U.S. battery factory with joint venture partner LG Chem of Korea. The companies hope to have a decision on a site in the first half of the year, spokesman Dan Flores said Thursday. Flores would not say where the company is looking but it’s likely to be near GM’s Spring Hill, Tennessee, factory complex, which is one of three sites the company has designated to build electric vehicles. A joint venture between GM and LG Chem currently is building a $2 billion battery factory in Lordstown, Ohio, near Cleveland, that will employ about 1,000 people. The site is fairly close to GM’s two other designated electric vehicle plants, one in Detroit and the other north of the city in Orion Township, Michigan. GM is likely to need far more battery capacity if it’s able to deliver on a …