What’s the future of electric vehicles?

What’s the future of electric vehicles? A 500 mile range.

Affordable electric vehicles have been limited by the range of conventional battery technology. The future of electric vehicles lies in innovation in battery technology.

Unfortunately, the technology for a range of 200 miles in a pure electric vehicle just isn’t there. Conventional Lithium-ion batteries don’t have the energy efficiency to store the energy necessary to propel a car for a range of 150 miles, let alone lofty 300 or 500 mile ranges. The problem is with the energy density[1] of modern batteries. Energy density is the amount of energy that a battery can hold per kilogram of material. If you want more energy, you need to either increase the amount of energy the battery can hold (raising the energy density) or add more batteries (raising the weight). The problem with adding more batteries is that it’s self defeating! The more batteries you add, the heavier the vehicle becomes. The heavier a vehicle becomes, the more energy The Tesla’s batteries have an energy density of roughly 150 watt-hours per kilogram. To achieve a range of 300 – 500 miles, electric vehicles need batteries with an energy density of 1500 – 2000 watt-hours per kilogram. That’s 10 times the current energy density.

Enter The Battery 500 Project. Researchers at IBM gathered some of the world’s leading experts in the field of electrical energy storage and advanced battery technologies in San Jose, California, to brainstorm on how to create next-generation rechargeable batteries capable of storing ten times more energy than today’s most powerful Lithium-ion batteries.

One idea brought forth is Lithium Air Batteries[2]. Lithium Air batteries are batteries consisting of lithium anodes coupled to oxygen through an air cathode. Theoretically, the capacity of the battery is limited only by the lithium contained within the battery.
Lithium-air batteries are unique in that instead of being a sealed system, they couple to atmospheric oxygen—essentially harnessing the oxygen in the air as the cathode of the battery. Since oxygen enters the battery on-demand, it offers an essentially unlimited amount of reactant, metered only by the surface area of its electrodes. IBM believes its nanoscale semiconductor fabrication techniques can increase the surface area of the lithium-air battery's electrodes by at least 100 times, enabling them to meet the goals of the project. [3]

Lithium Air batteries will be able to reach the energy density (1500 watt-hours per kilogram of material) necessary for electric vehicles to reach a range of 500 miles.

Khalil Amine is the manager of the Advanced Lithium battery Technology group at Argonne National Laboratory and manages the development of high-powered batteries for hybrid electric vehicles. Lithium-ion batteries made with Argonne’s materials can store up to 30 percent more energy than Lithium-ion cells now on the market. [4]

The Battery 500 Project

Khalil Amine on Lithium-air Batteries

1 Wikipedia article on Energy Density. Great reading for anyone interested in the breakdown of energy density by storage type (nuclear fusion, hydrogen batteries, lithium ion batteries) (http://en.wikipedia.org/wiki/Energy_density)
2 Wikipedia article on Lithium air batteries. http://en.wikipedia.org/wiki/Lithium_air_battery
3 Smarter Technology on The Battery 500 project http://www.smartertechnology.com/c/a/Technology-For-Change/Battery-500-P...
4 Carlist on Khalil Amine and the accomplishments of the Argonne National Laboratory http://www.carlist.com/blog/?p=1062