Prabakhar Patil is the CEO of Compact Power Inc, the subsidiary of LG Chem that has been working with GM to produce the Volt's battery packs.
I recently had the chance to ask him about the cost of lithium-ion batteries. As some sources suggest cost could be as high as $1000 kwh, I asked him what the actual cost is in today's market. My question with his explanation follows:
What is the cost of lithium ion automotive batteries?
Is its risky or dangerous to quote direct numbers.
At the cell level, in consumer applications, 100% of the nominal capacity at the beginning of life is somewhere on the order of $350 per kwh.
First, we have to keep adding factors for in a vehicle application, when you look at it as a 10 year life and you have this 25% degradation, then your denominator goes down by 25%.
Secondly, if you're not using all of the capacity, just the combination of those two factors will effectively cut the denominator in half in terms of usable capacity at the end of life as opposed to nominal capacity at the beginning of life. And that will raise the price in dollars per kwh, if you do it in terms of usable capacity at the end of life, by a factor of two
Third, if you add all of the other stuff you have to put in the pack, and it depends on what you consider inside the pack as opposed to outside, because that depends on vehicle architecture. So that’s why it gets very fuzzy and inconclusive to talk about gross level numbers unless you know specifically on how they are being defined.
The other perspective is that lithium ion in the 17 years since it was first introduced has come down by a factor of 14 in terms of dollars per kwh and it's not done. It will continue to come down not at the same rate, but I fully expect over the next 5 to 10 years for the cost to get better by anywhere from a factor of 2 to 4 in terms of dollars per kwh as compared to where we are now.
One of the things that has nothing to do with the cell or any technology itself, is at the end of life if the battery still has 70 to 75% of its power and energy left. Why throw it away when you can recapture it? If you could capture that residual value by effectively leasing the battery and putting it to work again in a utility application, at 50% of its initial value, it will cut the effective cost by a factor of two.