Bosch claims they will commercialize 400 watt hour per kilogram solid state batteries at half the price of today's batteries by 2020

http://nextbigfuture.com/2015/09/bosch-claims-they-will-commercialize.html

117 watt-hours per kilogram: The level Tesla and Panasonic were achieving in 2008 for the Roadster
200 watt-hours per kilogram: The level Sonny Wu, Boston-Power's CEO, says the company is achieving today
250 watt-hours per kilogram: The approximate energy density of the batteries in the Tesla S
400 watt-hours per kilogram: According to Tesla's Elon Musk, the concept of battery-powered transcontinental airplanes becomes “compelling” once batteries hit 400 watt-hours per kilogram
400 watt-hours per kilogram: The level that battery aspirant and ARPA-E grant recipient Envia claimed it could achieve