Robin Rogers, a professor of chemistry at the University of Alabama, says the challenge is finding “commodity ionic liquids” with the right set of properties that can completely change the economic equation for metal-air batteries. “It’s not impossible,” he says. “I look at ionic liquids and say, take a step back, because you need to do it in a completely different way.”
Friesen downplays the cost concern, pointing out that the liquids become quite economical when developed in-house in large volumes. He’s careful, however, not to say too much about the ionic liquids his team has developed, revealing only that there are “several contenders that seem to work well.”
Friesen is also cautious when talking about the other key component of Fluidic Energy’s research: a metal electrode structure that overcomes the problem of dendrite formation. These branch-like structures can grow on, for example, a zinc electrode and cause a metal-air battery to short-circuit. Dendrite formation happens in rechargeable batteries when the chemical reactions are reversed, limiting the number of charging cycles. Fluidic Energy has developed an electrode scaffold with multi-modal porosity, meaning it has a range of pore sizes down to as small as 10 nanometers. The scaffold surrounds the metal, in this case zinc, and can prevent dendrites that form during charging.
With the ability to eliminate evaporation, boost voltage and eliminate dendrites, “we’re working now on taking it to the next level,” says Friesen. “It’s about taking everything we’ve done over the last four years and leveraging that work into a battery that looks and feels just like a lithium battery, but has energy densities far beyond that.”
This would mean that energy storage would no longer be a limiting factor for renewable energy, and electric vehicles that could travel 400 to 500 miles on a single charge, he says, “at a cost just a little over lead-acid batteries.”