Aug. 2, 2012 at 3:52 PM ET
A battery technology that was all the rage in the era of disco is getting a fresh look thanks to a dose of the same stuff in a bottle of Pepto-Bismol.
Interest in rechargeable iron-air batteries peaked during the 1970s energy crisis. But the batteries never took off due to their low efficiency and short life spans.
Sri Narayan, a chemist at the University of Southern California, appears to have hit on a formula that makes the batteries 10 times more efficient, a key step for their viability in the 21st century.
"Iron is cheap and air is free," he said in a news release. "It’s the future."
Iron-air batteries use chemical energy generated by the oxidation of iron plates that are exposed to oxygen in the air. This is a process similar to rusting.
The problem was a competing chemical reaction of hydrogen inside the battery that sucked away about 50 percent of the battery’s energy, making it too inefficient for practical applications.
Narayan and colleagues added a bit of bismuth sulfide, part of the active ingredient in Pepto-Bismol, to the battery’s electrode. This shut down the wasteful hydrogen generation, reducing energy loss to just 4 percent.
The loss of hydrogen generation also improved discharge rates.
The improvements advance the prospect of iron-air batteries becoming "a sustainable large-scale energy storage solution," Narayan and colleagues write in the Journal of the Electrochemical Society.
Ultimately, these batteries could store wind and solar energy for use when the air is still and the sun is hiding behind clouds or the other side of the planet.
That, in turn, could allow utilities to bring more wind and solar power online, reducing dependence of other forms of energy such as coal and natural gas.
The research was funded by the Advanced Research Projects Agency, an arm of the Department of Energy. More details are available here.