Battery news. The next step appears to be lithium-sulfur (I've known about these for some time). Supposedly these are planned to go into production in late 2018
http://www.sionpower.com/
500 Wh/kg ... more than double the energy density of current lithium-ion batteries. At that rate a 100 kWh battery pack (biggest Tesla) would weigh 200 kg. This is probably at the cell level; making it into an actual battery pack will make it weigh more. (The Bolt's 60-ish-kWh Li-ion battery pack weighs about 400 kg)
LG Chem owns that company. LG Chem is heavily involved in supplying EV components including for the Chevrolet Bolt.
The number of charging cycles still needs work but I'm sure they're not done development. Even at 400 full charge/discharge cycles, if that is 500 km per cycle which is plausible at that energy density, that's 200,000 km ...