Batteries of the future charge ahead

Aqueous zinc-ion batteries (AZIBs) are emerging as a promising solution, offering low-cost energy storage derived from abundant resources. Scientists at Flinders University are leading efforts to develop simple and efficient polymer AZIBs using organic cathodes, advancing sustainable energy storage technology.

“Aqueous zinc-ion batteries could have real-world applications,” said Associate Professor Zhongfan Jia, a nanotechnology researcher in the College of Science and Engineering at Flinders University.

The increasing reliance on LIBs for electric vehicles and portable electronic devices has contributed to resource shortages and supply chain issues for strategic metals like lithium and cobalt. Additionally, the improper disposal of millions of spent batteries has created significant environmental concerns, a problem AZIBs may help to address.

Jia explained: “AZIBs stand out among alternative battery technologies because of the much higher abundance of zinc in the earth’s crust, which is ten times more than lithium. They also offer low toxicity and high safety.”

AZIBs typically employ zinc metal as an anode and either inorganic or organic compounds as a cathode. While much progress has been made in enhancing zinc anodes, developing high-performance cathodes remains a critical challenge. Jia’s team is working to overcome this hurdle by leveraging nitroxide radical polymer cathodes, which are derived from inexpensive commercial polymers. They have optimised the battery’s performance using low-cost additives, making strides toward affordable, scalable solutions.

“Our research reevaluated the use of high redox potential nitroxide radical polymer cathodes in AZIBs, achieving the highest mass loading to date,” Jia said, referencing a recent article published in Energy Storage Materials.

The study, led by master’s student Nanduni Gamage and postdoctoral fellow Dr Yanlin Shi, developed a lab-scale pouch battery using a low-cost polymer (approx. $20 per kg), a non-fluorinated Zn(ClO4)2 electrolyte, and BP 2000 carbon black ($1 per kg) without binder. This design provided a capacity of nearly 70 mAh g⁻¹ and a discharge voltage of 1.4V. With a mass loading of 50mg cm⁻², the pouch battery delivered 60 mAh, sufficient to power small devices such as an electric fan and a model car, demonstrating its potential in real-world applications.

The study was a collaborative effort, involving researchers from Flinders University and international experts, including Dr Jesús Santos-Peña from Université Paris Est Créteil CNRS in France. The research team is part of the Flinders University Institute for Nanoscale Science and Technology.

In a related development, the team, in collaboration with Griffith University, recently advanced organic radical/K dual-ion batteries, offering another potential alternative to relieve the global dependence on lithium-ion batteries.