Production of future low-cost aqueous zinc-ion batteries for large-scale sustainable energy storage

As global demand for lithium-ion batteries rapidly depletes raw material supplies, experts are looking for safe, affordable and reliable alternatives to rechargeable batteries.

Aqueous zinc-ion batteries (AZIBs) could be the solution to producing low-cost alternatives from abundant raw materials, and Flinders University scientists are leading the way in producing simple, practical polymer AZIBs using organic cathodes for more sustainable energy storage technology.

“Aqueous zinc-ion batteries could have real-world applications,” says Zhongfan Jia, associate professor of chemistry and nanotechnology researcher in the College of Science and Engineering at Flinders University.

From electric vehicles to portable electronics, the demand and consumption of lithium-ion batteries (LIBs) has led to resource shortages and supply chain issues for strategic metals, including lithium and cobalt.

Meanwhile, millions of used batteries, most of which are not properly recycled, have generated enormous waste and environmental risks, which future alternatives such as AIZBs promise to reduce.

“Among these alternatives, AZIBs stand out for the much higher abundance of zinc in the Earth’s crust (10 times more than lithium), as well as for their low toxicity and high safety.”

AZIBs typically use metallic zinc as the anode and inorganic or organic compounds as the cathode. Although significant work has been devoted to improving the stability of zinc anodes, high-performance cathodes are needed and remain a major challenge.

“Our research aims to improve conductivity using nitroxide radical polymer cathodes made from low-cost commercial polymers and to optimize battery performance using low-cost additives,” says Associate Professor Jia, who leads a research group working on sustainable polymers for energy and the environment.

“Our work re-evaluated the use of high-redox potential nitroxide radical polymer cathodes in AZIBs and produced the highest mass loading to date,” he says, referring to a new online journal article in the Journal of Power Resources.

The study, led by Flinders master’s student Nanduni Gamage and postdoctoral researcher Dr Yanlin Shi, developed a lab-made pouch battery using a large-scale polymer (at a cost of about $20/kg), non-fluorinated Zn(ClO)₄)₂ electrolyte and carbon black BP 2000 ($1/kg) without binder to provide a capacity of nearly 70 mAh g^-1 and an average discharge voltage of 1.4 V.

“Morphological engineering of PTAm@CNTs cathode for high-efficiency dual potassium-ion battery” was published in the Energy Resources Journal and “Conversion of a low-cost industrial polymer into organic cathodes for high-mass loading aqueous zinc-ion batteries” was published in Energy storage materials.

With a mass load of 50 mg cm^-2The pocket battery had a capacity of 60mAh, which can easily power a small electric fan and a model car.

The study’s collaborators included Dr Jesús Santos-Peña, from Université Paris Est Créteil CNRS in France, and other experts from Flinders University’s Institute for Nanoscale Science and Technology.

In collaboration with Griffith University, the team also recently developed organic radical/dual-K-ion batteries, a technique that can also reduce reliance on lithium-ion batteries.