Filling up an electric car battery like a gas engine

Check out this idea: a next-generation electric car where you could refuel the battery’s electrolyte in the same way you’d fill up an internal combustion car at the gas station. Sound crazy? Well, a startup called Eos Energy Storage is researching a next-generation hybrid flow battery made from zinc and air that could provide such a scenario.

The refillable flow electric car battery isn’t the company’s first target product — that would be a low cost zinc air grid battery — but it’s the firm’s most unusual. Eos Energy Storage President Steve Hellman explained to me how the hybrid flow battery works in an interview at the ARPA-E event on Monday, and said the application is possible because the company uses air for its cathode, zinc as its anode and a liquid electrolyte.

A battery is made up of an anode on one side and a cathode on the other, with an electrolyte in between. For a zinc battery, zinc ions travel from the anode to the cathode through the electrolyte, creating a chemical reaction that allows electrons to be harvested along the way. Eos could create a system that could plug into one of its used flow batteries and pump out the used electrolyte, with the zinc dissolved in it, and pump in new electrolyte with new zinc to created a newly charged battery. Envision pulling into a gas station and taking a few minute to fill ‘er up with electrolyte.

O.K., the idea is still in the very earliest stages of research and development and concept. And technologies that try to build entirely new infrastructures tend to struggle with capital costs (where are all the natural gas cars or refuelable fuel cell powered laptops?). But Eos says an electric car that utilizes its flow technology could theoretically cost $25,000, have a range of 400-miles and take 3 minutes to charge.

Eos Energy won’t even be commercializing its first product, the grid battery, until late 2013, or early 2014. That initial product could potentially be a game changer for the power grid, providing low cost, long lasting energy storage, and delivering a battery cell that costs $160 per kWh, lasts 30 years and is made up of everyday benign materials.

Scientists have been working on using air (and water) as the cathode for batteries for half a century. But Eos Energy’s founder and inventor Steven Amendola discovered a breakthrough with his original design of the bi-directional air cathode that could last for 10,000 cycles (or around three decades). The company has largely been funded by its management team, but is in the process of closing a funding round from strategic investors for scaling up its first grid zinc air battery.

Image courtesy of Raindog.