The 800-km battery lithium-ion batteries are played out. Next up: lithium-air

Proposition: Electric cars will remain mostly niche products until they have a range of 800 kilometers, or roughly 500 miles, with an affordable battery. That's as far as most people would want to drive in a day, and then they have all night to recharge. That's how we came up with a figure of 800 km-or a nice round 500 miles-as the goal for our R&D project, Battery 500. It began in 2009 at the IBM...