Ramez Naam, author of The Infinite Resource: The Power of Ideas on a Finite Planet, recently explained that lithium-ion batteries have a fifteen year history of exponential price reduction. Between 1991 and 2005, the capacity that could be bought with $100 went up by a factor of 11. The trend continues through to the present day.
SolidEnergy calculates that its materials could be used to make battery packs that cost $130 per kilowatt-hour, in line with U.S. Department of Energy goals for making electric vehicles affordable. Battery pack costs are typically kept secret, but estimates range from $250 to $500 per kilowatt-hour for packs in commercial electric vehicles.The 85 KWh battery pack for a Tesla S would go from $20,000 to $40,000 down to about $11,000.
Lithium ion could get even cheaper if only from economies of scale from factories that are ten times larger in China.Lithium Sulfur batteries are getting close to commercialization. They have the potential to drive costs to about $60 per KWh. This would be about $5000 for a Tesla S battery pack.