A plain-looking warehouse near Detroit is being transformed into a state-of-the-art lithium-ion battery assembly plant. General Motors Co. (GM) is investing $43 million in the facility to mass-produce battery packs for the Chevrolet Volt and other extended-range electric vehicles. When the 160,000-square-foot facility opens next year, it will be the first lithium-ion battery manufacturing plant in the U.S. operated by a major automaker.

Lithium-ion batteries are today's hot technology in the auto industry. However, the devices have traditionally been expensive to produce. To capture a piece of the lithium-ion battery business, American manufacturers need to invest heavily in automated assembly lines.

Future generations of green vehicles will depend on in-wheel motors. The technology involves a combination to wheels, tires, motors, brakes, steering, suspension and cooling systems. It eliminates the need for traditional components such as engines, transmissions, differentials and transmission shafts, which can result in a 10 percent to 25 percent weight reduction and a 20 percent to 30 percent fuel savings.

Despite big challenges, the potential is huge.