I find this report by the DOE on Lithium battery packs for cars actually promising instead of depressing. According to the DOE we are somewhere between 2x and 3x of appropriate cost before we have wide adoption by the market. Given that we are at the start of the electric car age, I find this perfectly acceptable. More sources: DOE.

Cost – The current cost of Li-based batteries is approximately a factor of two too high on a kW basis. The main cost drivers being addressed are the high cost of raw materials and materials processing, the cost of cell and module packaging, and manufacturing costs.

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Life – The calendar life target for hybrid systems (with conventional engines) is 15 years. Battery life goals were set to meet those targets. A cycle life goal of 300,000 cycles has been attained in laboratory tests. The 15-year calendar life is yet to be demonstrated. Although several mature electrochemistries have exhibited a 10-15 year life through accelerated aging, more accurate life prediction methods need to be developed.”