Low cost energy storage

A team of researchers has developed a cheap, rechargeable and eco-friendly battery that could be used to store energy at solar power plants for a rainy day.

 

Led by Sri Narayan, professor of chemistry at the USC Dornsife College of Letters, Arts and Sciences, the team developed an air-breathing battery that uses the chemical energy generated by the oxidation of iron plates that are exposed to the oxygen in the air — a process similar to rusting. "Iron is cheap and air is free,"Narayan said. "It's the future."

 

As currently developed, Narayan's batteries have the capacity to store between eight and 24 hours' worth of energy. His patent is pending, and both the federal government and California utilities have expressed interest in the project.

 

Iron-air batteries have been around for decades — they saw a surge in interest during the 1970s energy crisis but suffered from a crippling problem: A competing chemical reaction of hydrogen generation that takes place inside the battery (known as hydrolysis) sucked away about 50 percent of the battery's energy, making it too inefficient to be useful.

 

Narayan and his team managed to reduce the energy loss down to 4 percent, making iron-air batteries that are about 10 times more efficient than their predecessors. The team did it by adding a very small amount of bismuth sulfide into the battery. Bismuth, which happens to be part of the active ingredient in Pepto-Bismol and helps give the pink remedy its name, shuts down the wasteful hydrogen generation.