In Brief Four years ago, Ford and South Korean battery maker SK On struck a deal to form a joint venture and spend $11.4 billion to build factories in Tennessee and Kentucky that would produce batteries for the next generation of electric F-Series trucks.The factories live on; the joint venture will not. SK On, a subsidiary of SK Innovation, said Thursday it reached an agreement with Ford to end the joint venture. The two companies will divide the assets: Ford will take ownership and operation of the twin ...