A zinc-air battery developed by researchers and Stanford University may provide an economical alternative to lithium-ion batteries for use in renewable energy plants. When adopted into renewable energy plants, these batteries may hold up to one megawatt (MW) of electricity or more.
Renewable energy sources like solar and wind do not provide power at all times. While solar power is susceptible to clouds and night, wind is not constant, generating varying amounts of power over time. To combat this problem, these power generation systems need to have large batteries in them, that store energy of a megwatt or more when it is plentiful, for use when needed.
Current models for industrial power storage are made from expensive materials, and require the use of catalysts made from precious metals, including platinum. The catalysts is needed to increase the occurrence of necessary chemical reactions in the battery. Between the cost of the battery itself and the catalyst made of platinum or iridium, the cost of renewable energy becomes far greater.
Zinc-air batteries use oxygen and zinc contained in a liquid electrolyte. This combination results in a chemical reaction which generates electricity. When the batteries are recharged, the reaction reverses itself, reforming zinc and oxygen. The battery is then ready to be used once again.
Zinc, an inexpensive metal, has been used in batteries before, but the reactions have always been too slow for industrial use. The new zinc-air batteries developed at Stanford uses an inexpensive catalyst that could make these new designs much more attractive from an economic standpoint. The new catalyst was created from a mixture of cobalt oxide, a nickle-iron mixture and carbon nanomaterials.
"Zinc-air batteries are attractive because of the abundance and low cost of zinc metal, as well as the non-flammable nature of aqueous electrolytes, which make the batteries inherently safe to operate," Hongjie Dai, chemistry professor at Stanford and the lead author of the study, said.
These new batteries could be used to allow wind and solar farms to compete with natural gas to supply power during times of low production. Storage of power generated at wind and solar farms may not be the only application for this new technology, however. Researchers hope that their new battery will become common in everyday items.
"There have been increasing demands for high-performance, inexpensive and safe batteries for portable electronics, electric vehicles and other energy storage applications. Metal-air batteries offer a possible low-cost solution." Dai said.
The research leading to this new form of power storage device was funded in part by Intel.
Results of the research were published in Nature Communications.