Fraunhofer Institute is working on a new redox flow battery technology for electric vehicles(EVs). Rather than plugging in your EV or changing out the battery, you simply empty out the “discharged electrolyte fluid” and refill with new charged fluid.
According to Fraunhofer, changing the fluid will be a quick and easy process similar to gassing up your car. Redox flow batteries offer a solution to the long hours of charging currently required for li-ion batteries. “These batteries are based on fluid electrolytes. They can therefore be recharged at the gas station in a few minutes – the discharged electrolyte is simply pumped out and replaced with recharged fluid,” says engineer Jens Noack from ICT. “The pumped-off electrolyte can be recharged at the gas station, for example, using a wind turbine or solar plant.”
Redox flow batteries work by having
two fluid electrolytes containing metal ions flow through porous graphite felt electrodes, separated by a membrane which allows protons to pass through it. During this exchange of charge a current flows over the electrodes, which can be used by a battery powered device.
The principal has been around for a long time but regular redox flow batteries don’t store even the energy found in a li-ion battery. Previous redox flow batteries would have to be recharged four times just to go the distance of a normal li-ion battery. But Fraunhofer has increased the energy storage so that it will go four to five times further on a charge making it more competitive with li-ion batteries.
The improved redox flow batteries with an easy recharge method and existing infrastructure (assuming of course that the refueling would use existing gas pump technology) provides a more economical infrastructure. The vast and expensive electric car infrastructures being built by Better Place and Coulomb would no longer be needed. Being able to use renewable energy provided by wind, solar, wave or hydro power to recharge the electrolyte fluid also cuts down on greenhouse gas emissions.
Fraunhofer and the University of Applied Sciences, Ostphalia, in Wolfenbüttel and Braunschweig are currently “testing electric drives and energy storage units” while continuing to optimize the battery.
The redox flow battery might not be a new concept but perfecting it for use in EVs will require further research and testing. For an old idea, it will take some time to make into an electric vehicle near you.