Scientists at the University of Southern California (USC) have developed an organic, rechargeable battery that could be scaled up for use in power plants, making the energy grid more resilient and efficient by creating large-scale capacity to store energy for use as needed.


The USC team claims the water-based organic battery, which uses no metals or toxic material, is long-lasting and built from cheap and ecofriendly components. 


“The batteries last for about 5,000 recharge cycles, giving them an estimated 15-year lifespan,” said Sri Narayan, professor of chemistry at the USC Dornsife College of Letters, Arts and Sciences and author of a paper published by the Journal of the Electrochemical Society describing the new batteries. “Lithium-ion batteries degrade after around 1,000 cycles and cost 10 times more to manufacture.”


The batteries could pave the way for renewable-energy sources to make up a greater share of the nation’s energy generation. The inherent intermittency makes it difficult for power companies to rely on renewables to meet consumer demand. With batteries to store surplus energy and then dole it out as needed, that sporadic unreliability could cease to be an issue.


“‘Mega-scale’ energy storage is a critical problem in the future of the renewable energy, requiring inexpensive and ecofriendly solutions,” Narayan said.


The new battery is based on a redox flow design, similar to a fuel cell. This design has the advantage of decoupling power from energy. The tanks of electroactive materials can be made as large as needed, increasing the total amount of energy the system can store. The central cell can also be tweaked to release that energy faster or slower, altering the amount of power (energy released over time) that can be generated.


Through a combination of molecule design and trial-and-error, they found that certain naturally occurring quinones—oxidized organic compounds—could dissolve in water and 
minimize impact on the environment.


“These are the types of molecules that nature uses for energy transfer,” he said.


Currently, the quinones needed for the batteries are manufactured from naturally occurring hydrocarbons. In the future, the potential exists to derive them from carbon dioxide, Narayan said.


The team has filed several patents in regard to design of the battery and next plans to build a larger scale version.