Lithium-ion cell and battery pack assembly for Nissan Leaf electric car in Sunderland, U.K., plantEnlarge Photo
Relatively low lithium-ion battery-cell prices are crucial to keeping the prices of electric cars reasonable.
But how much does the volatility of the price of lithium itself affect the prices of those cells?
Global lithium prices have doubled over the last six months, leading to a scramble for new supplies of the metal.
Researchers Rebecca Ciez and Jay Whitacre analyzed multiple lithium-ion cell chemistries, and concluded that large increases in the global price of lithium won't translate into large increases in the price of battery cells.
For analysis, Ciez and Whitacre selected two prismatic cell designs, and two lithium-ion cell chemistries.
Battery pack assembly for 2015 Chevrolet Spark EV electric car at GM's Brownstown, Michigan, plantEnlarge Photo
Researchers concluded that even a price more than three times as high—from $7.50 per kilogram to $25 per kilogram—would not lead to an increase in battery cost of the same magnitude.
The maximum increase in cost per kilowatt-hour for the four batteries studied would be less than 10 percent, researchers said.
To realize even a 15-percent increase in cell costs, lithium prices would have to rise to between $36 per kg and $87 per kg, they said.
The researchers believe those prices are "unsustainably high," and would "trigger other lithium producers to enter the market," increasing supply and eventually lowering prices.
Lithium is plentiful; the current sources are not the only ones available, but merely the cheapest, the researchers noted.
Nissan prototype 60-kWh battery pack - Nissan Technical Center, October 2015Enlarge Photo
High lithium prices or not, carmakers and battery suppliers still need to achieve lower costs for lithium-ion cells.
For mass adoption of electric cars to take place, cells will have to be cheap enough to allow for comparable range to internal-combustion cars, at a comparable price.
This has led researchers to look beyond the current lithium-ion chemistry for more cost-effective designs, although lithium-ion will likely remain dominant for the time being.