In related research there's the ORNL solid state 10,000 cycle Li-Ion battery.
http://insideevs.com/ornl-solid-state-battery-test-90-original-capacity-10000-cycles/
As you'll see (and as commented in that link), one of the biggest problems is maintaining efficiency with higher charge/discharge rates. A lot of the promising tech falls over badly on this point and that's where major delays to market occur trying to fix it.
Biting the hand that feeds IT
