The slow pace of the lithium-ion technological progress is not its only shortcoming. There’s more:
And this is not all. At the current rate of consumption lithium will start to become scarce at current prices by around 2020. To open up today’s non-economical lithium deposits, prices would need to double. Cobalt, which is a component of lithium-ion batteries, is already scarce today and in addition to this there have been cases of human exploitation in its mining, as well as lack of proper handling from mining companies causing contamination of rivers and soils.