New zinc-iodine battery achieves over 60,000 charge cycles, charges in 3 minutes

Flinders University researchers have developed a high-performing, safe, and sustainable aqueous zinc-iodine rechargeable battery (AZIB) as an alternative to lithium-ion batteries (LIBs) for large-scale energy storage. Interestingly, it retains 60,000 charge-discharge cycles and charges in three minutes. “Rechargeable aqueous zinc-iodine batteries are shaping up as a viable alternative to lithium-ion batteries for large-scale energy storage, and our group is now working with industry to establish a prototyping platform for this battery system,” said Zhongfan Jia, Associate Professor in Chemistry, Matthew Flinders Fellow at Flinders University’s College of Science and Engineering. The shuttle effect fix Lithium-ion batteries dominate electric vehicles and portable tech, but come with a heavy toll. These batteries are expensive, prone to fire risks, and produce massive environmental waste. Australia alone generates roughly 3,300 tonnes of lithium battery waste annually, a figure projected to skyrocket past 136,000 tonnes by 2036. Zinc-iodine alternatives offered a water-based, non-flammable escape route. But the face the “shuttle effect,” where polyiodine species leak through the battery separator and degrade performance over time. That is where starch changes the game. The team solved this by creating a host material using a low-cost, biodegradable cyclodextrin-based polymer (derived from starch) that traps and releases polyhalides. Cyclodextrin molecules are widely used in cosmetics and food. The Flinders team engineered a microscopic cage. Its hydrophilic exterior and hydrophobic interior trap and release polyhalides on demand, stopping the leakage cold. “This system offers a new approach to mitigate polyiodide shuttling by using polymers derived from inexpensive, biodegradable oligosaccharides, thereby enabling sustainable and long-lasting aqueous zinc-iodine batteries,” said Associate Professor Zhongfan Jia, lead researcher on the project. The performance stats read like a wishlist for large-scale grid storage. Operating at 1.3 to 1.4 volts, the battery delivers a capacity of 200 mAh/g over 8,000 cycles when fully charged in seven minutes. Drop the target capacity slightly to 150 mAh/g, and a ultra-fast three-minute charge yields over 60,000 cycles. As per the study, the battery degrades at an almost imperceptible rate of 0.0001% to 0.0003% per cycle, explaining how it achieves over 60,000 cycles. Australia’s zinc advantage Zinc-based batteries offer a far safer, cost-effective, and highly accessible alternative to lithium-ion systems without sacrificing performance. These batteries eliminate fire risks while matching or exceeding lithium-ion in both specific energy and energy density. Their low cost and abundant raw materials have made them the dominant global standard for single-use energy storage. Lithium processing is currently heavily concentrated in China, leaving countries vulnerable to supply shocks. The discovery carries major economic implications for Australia. While the nation struggles with lithium processing, it sits on major known zinc reserves. AZIBs typically rely on zinc metal as an anode, giving Australia a significant strategic advantage in the transition to next-generation energy storage. The nation holds between 20 percent and 28 percent of the world’s total known zinc reserves. First co-author Shangxu Jiang notes that leveraging these vast domestic resources could anchor a safer, sovereign energy storage industry The Flinders lab is now working directly with industry partners to build a commercial prototyping platform. Hence, it looks like the next green energy transition might not be powered by scarce, fiery metals, but by zinc and ordinary plant sugar. The findings were published in the journal Angewandte Chemie. Get the latest in engineering, tech, space & science - delivered daily to your inbox.Mrigakshi is a science journalist who enjoys writing about space exploration, biology, and technological innovations. Her work has been featured in well-known publications including Nature India, Supercluster, The Weather Channel and Astronomy magazine. If you have pitches in mind, please do not hesitate to email her.