Whether that’s possible with conventional lithium-ion technology is a matter of debate. Though some involved in battery manufacturing say the technology still has room for improvement, the NAS report, for one, notes that although lithium-ion batteries have been getting far cheaper over the last decade, those reductions seem to be leveling off. It concludes that even under optimistic assumptions, lithium-ion batteries are likely to cost around $360 per kilowatt-hour in 2030.
The U.S. Department of Energy, however, has far more ambitious goals for electric-vehicle batteries, aiming to bring the cost down to $125 per kilowatt-hour by 2020. For that, radical new technologies will probably be necessary. As part of its effort to encourage battery innovation, the DOE’s ARPA-E program has funded 10 projects, most of them involving startup companies, to find “game-changing technologies” that will deliver an electric car with a range of 300 to 500 miles.
The department has put $57 million toward efforts to develop a number of very different technologies, including metal-air, lithium-sulfur, and solid-state batteries. Among the funding recipients is Pellion Technologies, a Cambridge, Massachusetts-based startup working on magnesium-ion batteries that could provide twice the energy density of lithium-ion ones; another ARPA-E-funded startup, Sion Power in Tucson, Arizona, promises a lithium-sulfur battery that has an energy density three times that of conventional lithium-ion batteries and could power electric vehicles for more than 300 miles.
The ARPA-E program is meant to support high-risk projects, so it’s hard to know whether any of the new battery technologies will succeed. But if the DOE meets its ambitious goals, it will truly change the economics of electric cars. Improving the energy density of batteries has already changed how we communicate. Someday it could change how we commute.