An ‘instantly rechargeable’ battery could galvanize the electric car industry

A battery as simple as this may revolutionize the auto industry if it takes off. (Purdue Research Foundation)

A battery as simple as this may revolutionize the auto industry if it takes off. (Purdue Research Foundation)

It may be a few years out, but one day vehicle owners could pull up to what once was a gas station pump and fill the tank with a solution of charged electrolytes to fuel their trip.

A breakthrough battery has been developed at Purdue University in Indiana that could change how we power our electric vehicles — and instantly recharge them.

It’s a flow battery — a type of rechargeable battery composed of chemicals dissolved in positively or negatively charged liquids. These liquids usually are separated by a barrier membrane, often made of metal.

The new Purdue battery does not have a membrane. That’s an advantage. The membrane limits the life of a battery because it corrodes, eventually causing the battery to malfunction.

Here’s how the Purdue battery — called the IFbattery — works. IF stands for “immiscible fluid.” Immiscible means that battery components — the fluids — don’t mix, just like water and oil don’t mix. It’s a simple cocktail of polar solvents ethanol and water, to which salt is added. The salt renders the positive and negatively polarized solvents immiscible, creating a natural barrier.

“It’s a very different approach to what people have been doing in the past, says team leader John Cushman. This “membraneless” flow battery is the first of its kind.

Man holding test tube with flow battery in background (Purdue Research Foundation)
John Cushman, Purdue University professor of earth, atmospheric and planetary science and mathematics, led the team that developed the IFbattery for electric vehicles. Now they want to take it on the road. (Purdue Research Foundation)

The IFbattery has a lot going for it. Unlike the lithium-ion batteries used for everything from cellphones to electric vehicles to power grid storage, the IFbattery poses no fire or explosion risk. It is safe. It is also much cheaper to make, out of widely available materials. It does not require charging like the lithium-ion battery and does not pollute the environment with greenhouse gases or hazardous waste. All components are biodegradable.

What’s more, the battery generates something called “supercapacitance,” which means it has a high capacity to store energy. Cushman explains, “That allows you to get much stronger current, much higher power, than you would with a normal battery.” And that makes it suitable for vehicles.

“You never have to charge this thing up,” he says. The spent electrolytes — which can be recharged — are dropped off at a station. Then you fill the tank with charged electrolytes and you are on your way. He estimates the distance a tank of electrolytes could take a vehicle would be comparable to the distance a Tesla can go, 400 to 480 kilometers.

It hasn’t been road-tested yet, but if all goes well, the project will expand beyond the lab and eventually onto the highways — possibly within a decade. The researchers are seeking investors to make that happen.

“The science is basically done now. What we need now are engineers,” Cushman says. Mechanical or chemical engineers will take the next steps to develop new vehicles or retrofit kits for electric vehicles. A working model will probably take a couple of years, he says.

For a completely sustainable loop, spent electrolytes from the IFbattery could be shipped from the fueling stations where they are dropped off to solar or wind farms for reprocessing.

“You don’t have to sit around for two hours to charge. That’s the beauty of it,” Cushman says.

To learn more about the IFbattery project, check out this video:

By: Lea Terhune