Published: March 8, 2017 By

University of Colorado Boulder engineers have received a $3 million grant from the to develop better membranes for more efficient and cost-effective large-scale battery technology as a means of storing energy generated by methods such as wind and solar.

The research project, led by Richard Noble, Douglas Gin and Hans Funke of Ƶ Boulder’s , will focus on improving the sophisticated membranes hidden inside powerful flow batteries. Unlike small, self-contained consumer batteries (AAAs, for example), flow batteries use external tanks to store the chemicals needed for an electrical reaction. The chemicals are commonly separated by a semi-permeable membrane.

Historically, a key challenge of flow batteries has been perfecting the efficiency of their delicate membrane, which allows negatively-charged chloride ions to pass through but rejects unwanted ions. The membrane’s tiny, uniform pores are less than one nanometer wide, smaller than a single DNA molecule.

Current flow batteries use a variety of chemical solutions, but all-iron versions are considered attractive because they can use one of Earth’s cheapest and most abundant materials. The three-year grant from the DOE’s Advanced Research Projects Agency-Energy (ARPA-E) will include partners from the University of California San Diego and , a Portland, Oregon, company that specializes in all-iron flow batteries.

If researchers are successful in improving on the all-iron flow batteries, the outcome could be a highly efficient flow batter that costs less than $100 per kilowatt-hour — a significant cost improvement from current flow batteries on the market. Such batteries would offer a safe, low-maintenance solution for large-scale electrical energy storage — including the intermittent energy generated from wind and solar — for business or military use.

Gin and Noble have been working on nanoporous membrane technology for 15 years across a variety of applications, including water desalination and improving biohazard suits that can protect against chemical warfare agents.

Gin said the team is excited to retool the membrane technology invented at Ƶ Boulder for a new, more sophisticated application.

“Now we’re in that phase where we don’t have to make huge quantum leaps,” said Gin. “Small alterations with a system that’s fairly mature can start making a difference right away.”

a wind turbine

Photo: Tom Corser / Wikipedia