Reuters: General Motors Corp said it plans production of upgraded hybrid gasoline-electric vehicles in 2010 using more powerful lithium-ion batteries that promise to boost fuel economy by up to 20 percent. Lithium-ion batteries will be able to provide nearly three times the power of the nickel metal hydride batteries now used in most hybrid vehicles, while weighing far less and taking up less space, the automaker said. Widespread production of hybrid vehicles with lithium-ion …