Scientists have developed a water-based organic battery that is long lasting and built from cheap, eco-friendly components.

The new battery - which uses no metals or toxic materials - is intended for use in power plants, where it can make the energy grid more resilient and efficient by creating a large-scale means to store energy for use as needed.

“The batteries last for about 5,000 recharge cycles, giving them an estimated 15 year lifespan,” said Sri Narayan, professor of chemistry at the University of Southern California Dornsife College of Letters, Arts and Sciences and the corresponding author of the study.

“Lithium ion batteries degrade after around 1,000 cycles, and cost 10 times more to manufacture,” Narayan said.

Narayan collaborated with Surya Prakash, professor of chemistry and director of the USC Loker Hydrocarbon Research Institute, as well as USC’s Bo Yang, Lena Hoober—Burkhardt, and Fang Wang.

“Such organic flow batteries will be game-changers for grid electrical energy storage in terms of simplicity, cost, reliability and sustainability,” said Prakash.

Solar panels and wind turbines are inherently unreliable which makes it difficult for power companies to rely on them to meet customer demand.

With batteries to store surplus energy and then dole it out as needed, that sporadic unreliability could cease to be such an issue, researchers said.

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

The new battery is based on a redox flow design — similar in design to a fuel cell, with two tanks of electroactive materials dissolved in water.

The solutions are pumped into a cell containing a membrane between the two fluids with electrodes on either side, releasing energy.

The design has the advantage of decoupling power from energy.

The tanks of electroactive materials can be made as large as needed — increasing total amount of energy the system can store — or the central cell can be tweaked to release that energy faster or slower, altering the amount of power (energy released over time) that the system can generate.

While previous battery designs have used metals or toxic chemicals, Narayan and Prakash wanted to find an organic compound that could be dissolved in water.

Such a system would create a minimal impact on the environment, and would likely be cheap, they figured.

They found that certain naturally occurring quinones — oxidised organic compounds — fit the bill. Quinones are found in plants, fungi, bacteria, and some animals, and are involved in photosynthesis and cellular respiration.

The research was published in the Journal of the Electrochemical Society.