Interesting read. Talks about Tesla and batteries getting less expensive.

"The authors admitted that their data was imperfect due to secrecy surrounding business deals"

" “There are still R&D improvements to be made in, for example, anode and cathode materials, separator stability and thickness, and electrolyte composition,” Nykvist and Nilsson wrote. “Among these factors, input material cost is among the most important, and costs as low as US$300 per kWh due to such improvements have been discussed. Together with improvements due to economies of scale, a 12-14 percent learning rate is conceivable.”"

As long as that anode material doesn't change to aluminum I'm a happy guy..

http://arstechnica.com/science/2015/07/electric-vehicle-batteries-are-getting-cheaper-much-faster-than-we-expected/