High Performance Transportation Redox-Air Flow Cells
Most of today's electric vehicles (EVs) are powered by lithium-ion (Li-Ion) batteries--the same kind of batteries used in cell phones and laptop computers. Currently, most Li-Ion batteries used in EVs provide a driving range limited to 100 miles on a single charge, require several hours to recharge, and account for more than half of the total cost of the vehicle. To compete in the market with gasoline-fueled vehicles, EVs must cost less, drive farther between charges, and recharge more quickly.
Project Innovation + Advantages:
United Technologies Research Center (UTRC) will develop a proof-of-concept for an innovative new vehicle energy-storage system. The UTRC team is leveraging experience from a previous ARPA-E project focused on grid-scale energy storage, the GRIDS: Breakthrough Flow Battery Cell Stack project, to develop a high-performance redox-air flow cell (RFC) system for EVs. A flow battery is a cross between a traditional battery and a fuel cell. Flow batteries store their energy in external tanks instead of inside the cell itself. If successful, the RFC will: (1) store its energy in a liquid solution at ambient pressure in a conformable plastic tank; (2) be readily packaged inside of an EV given the RFC’s high power and energy densities, and (3) be rechargeable either onboard the vehicle like a conventional battery or by rapidly exchanging the discharged solution in the tank with charged solution at a refueling station. A novel recharging method will be employed to dramatically improve the round-trip energy efficiency for cells operating with an air electrode. Technologies like the RFC hold the potential to dramatically decrease the cost of EVs and enable greater adoption of EVs, allowing for increased energy efficiency, decreased petroleum imports, and substantial savings to the average consumer.