General Motors Co. and South Korea’s LG Corp. are partnering to develop a new lineup of battery-powered vehicles aimed at cutting the cost and time required to create electric cars. LG will cover half the cost of creating a future portfolio of electric and hybrid vehicles and then become GM’s supplier on anything the companies jointly create. The new arrangement increases LG’s role to include everything from on-board battery chargers to climate-control and possibly in-vehicle entertainment systems. GM hopes the partnership will help it move past rivals in the race to develop electric and gas-electric hybrid vehicles to meet the new U.S. fuel economy requirements.