Carlo U. Segre, Duchossois Leadership Professor and Director of the Center for Synchrotron Radiation Research and Instrumentation
Electric vehicles have been changing the way people move from place to place, ushering in an era of cleaner transportation. But according to Carlo U. Segre, Duchossois Leadership Professor, there is still one big hitch: the distance such vehicles can travel before needing to be recharged.
Segre says that the more affordable electric vehicles today can travel approximately 100 miles on a single charge, and for some drivers, this presents what he refers to as “range anxiety”—a predicament Segre is attempting to address through his research. Through a recently concluded $3.4 million project funded by the United States Department of Energy Advanced Research Projects Agency-Energy, Segre’s interdisciplinary team of Illinois Tech investigators and collaborators from Argonne National Laboratory designed and constructed a new kind of battery for such vehicles.
The range issue, Segre explains, is due to the limited energy per unit volume (or energy density) available in conventional lithium-ion batteries (li-ion) suitable for electric cars.
His group’s prototype EV scalable flow battery uses high-energy density nanoelectrofuel.
Li-ion batteries currently used in electric vehicles have the advantage of high cell voltage and energy density compared to previous generations of car batteries, but as Segre notes, there have always been drawbacks. In addition to energy-density limitations, there are multiple issues such as thermal runaway, gradual degradation of electrode materials, and long charging times. The group’s new approach greatly increases the energy density and lifespan of vehicle batteries, while eliminating the need for lengthy recharging altogether. The trick, Segre explains, is in the battery fuel itself.
“Our idea and patent is to load the electrochemical fluid with nanoparticles that are solid,” says Segre, who utilizes synchrotron radiation via Argonne’s Advanced Photon Source for much of his battery research efforts. “The key is making a stable suspension solution of nanoparticles, which increases the capacity of the fuel to store electrical energy.”
More conventional types of flow batteries have been around for a while, but low energy density limited their use to stationary applications, where the battery fluid can be stored in large tanks—too large to be practical for any vehicle. With the addition of nanoparticles, however, high energy densities can be achieved in a vehicle-ready battery. Perhaps most attractive is the fact that the discharged liquid fuel could potentially be replaced at a filling station in a matter of minutes. Currently, most electric cars must be charged overnight, once their batteries are depleted.
“This idea gets rid of the whole range issue,” Segre says. “If you can refill your battery tank, then it’s just like using normal fossil fuel.” That is, minus the harmful emissions.