While soaring demand for lithium-ion batteries pushes prices higher, Flinders University experts are making headway into launching a safe and more sustainable zinc-iodine rechargeable battery.
In their latest study, published in high-profile international journal Angewandte Chemie, the research team has designed an aqueous zinc-iodine battery (AZIB) that can be charged and discharged over 60,000 cycles.
"Rechargeable aqueous zinc-iodine batteries are shaping up as a viable alternative to popular lithium-ion batteries for large-scale energy storage and our group is now working with industry to establish a prototyping platform for this alternative battery system," says Associate Professor in Chemistry Zhongfan Jia, Matthew Flinders Fellow at Flinders University's College of Science and Engineering.
Iodine is one of the most effective materials for rechargeable batteries, with the potential to store a high amount of energy relative to its weight - around 211 mAh/g (milliampere-hours per gram).
However, one of the biggest challenges with this new battery technology is stopping iodine species from moving to places it shouldn't inside the unit.
The new battery uses a low-cost organic cyclodextrin-based polymer that helps store and control key chemicals, allowing it to charge quickly while maintaining performance. When fully charged in seven minutes, it can operate at 1.3 to 1.4 volts (V) with a capacity of 200 mAh/g over 8000 cycles, or charged in just three minutes and last for more than 60,000 cycles at 150 mAh/g.
Cyclodextrins are widely used in food, pharmaceutics and cosmetic ingredients. Their unique structure acts like a cage, locking iodine compounds in place and preventing them from disrupting the battery's operation.
"This system offers a new approach to mitigate polyiodide shuttling by using polymers derived from inexpensive, biodegradable materials, thereby enabling sustainable and long-lasting aqueous zinc-iodine batteries," says Associate Professor Jia.
Increasing demand and consumption of lithium-ion batteries (LIBs), from electric vehicles to portable electronic devices, have led to resource shortages, costly supply issues and major waste-recycling issues. Australia produces about 3300 tonnes of LIB battery waste a year, which is expected to rise to more than 136,000 tonnes by 2036.
The new batteries rely on zinc metal, a low-cost and widely available metal for which Australia holds the world's largest known zinc reserves, accounting for 20%- 28% of the global total.
"As a top global producer and exporter, we can use these zinc resources for safer energy storage, which is important for energy manufacturing in Australia," says first co-author Shangxu Jiang, a PhD student at Flinders University's Jia Lab which works on Sustainable Polymers for Energy and Environment.
Second first author Zhipeng Pei, working with senior co-author Flinders University Professor Michelle Coote, devised the computational modelling to support this project.
The article - 'Caging polyhalide anions in polycyclodextrin for long-lasting aqueous zinc-iodine batteries' (2026) by Shangxu Jiang, Zhipeng Pei, Yanlin Shi, Kai Zhang, Justin M Chalker, Sara J Fraser-Miller, Michelle L Coote and Zhongfan Jia - has been published in Angewandte Chemie International Edition (Wiley) DOI: 10.1002/anie.601068.
https://doi.org/10.1002/anie.601068
Acknowledgements: The project was funded by Australian Research Council (ARC) grants (DP230100587, DP230100642, DP260100462, DP230100555 and CE230100021) and support from the National Facility of the Australian National Computational Infrastructure and Flinders Deepthought, the Flinders University High Impact Collaborative Research Development Fund, YG Green Power Superstore and the Zhejiang Sci-Tech University.
The authors also acknowledge the Flinders Microscopy and Microanalysis and Australian National Fabrication Facility (ANFF) SA node for technical support and equipment.
