New Iron Air ‘Rust’ Deep Cycle Battery Unveiled

University of California (USC) researchers have developed a new type of deep cycle battery that uses the chemical energy generated by the oxidation of iron plates.
While iron-air batteries have been around since the 1970’s, a chemical reaction generating hydrogen resulted in around half of the stored energy being wasted; making them unviable. However, Sri Narayan, professor of chemistry at the USC Dornsife College of Letters, Arts and Sciences and his team have managed to reduce the loss to just 4%.
This was achieved by adding  a very small amount of bismuth sulfide into the battery, which shut down hydrogen generation while maintaining the battery’s environmentally friendly nature.
Featuring a charging efficiency of 96%, a twenty-fold increase in discharge rate capability and costing around a tenth of lithium ion batteries, Professor Narayan says the cheap, rechargeable and eco-friendly battery could be used to store electricity produced at solar farms. 
“Iron is cheap and air is free,” Narayan said. “It’s the future.”
Two years of research have gone into what is also being called the “rust battery” and the team are now working to make the battery store more energy with less material. $1.8 million in funding for the research came from the Advanced Research Projects Agency for Energy, a division of the U.S. Department of Energy.
Further details regarding the battery have been published in the Journal of the Electrochemical Society.
Cheap solar panels used to be the holy grail of renewable energy, but with that goal now attained the next major challenge is energy storage.
Other emerging battery and energy storage technologies we’ve reported on previously; some of which have already gone on to be used in commercial applications:
Zinc air
Iron phosphate
Molten salt 
Iron based flow
Vanadium based flow
Liquid metal
Silicon air
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