Flinders University Zinc-Iodine Battery Prototype Logs Over 60,000 Cycles

Researchers at Flinders University in Australia have built a zinc-iodine battery storage prototype that charged and discharged more than 60,000 times in laboratory testing, according to pv magazine.

The prototype is based on the team's aqueous zinc-iodine battery design. At its core sits a low-cost organic cyclodextrin-based polymer that stores and controls the key chemicals inside the cell while allowing the battery to charge quickly without losing performance.

The underlying work appears in the paper "Caging polyhalide anions in polycyclodextrin for long-lasting aqueous zinc-iodine batteries," published in Angewandte Chemie International Edition. The title points to the mechanism the researchers credit for the cycle count: trapping polyhalide anions inside the polymer structure rather than letting them migrate freely through the cell.

Cycle life is the metric that separates laboratory chemistry from bankable grid storage. A cell that survives 60,000 charge-discharge cycles in the lab is being characterised for duty far beyond what a consumer-electronics cell is asked to do. Polyhalide shuttling has long been the failure mode that shortens the working life of iodine-based aqueous cells, and the cyclodextrin polymer is the component the Flinders team put in place to address it.

The chemistry choice also matters on cost. The polymer is described as low-cost and organic, and the cell is aqueous rather than solvent-based. Zinc and iodine sit outside the lithium and nickel supply chains that dominate current grid-scale battery procurement, though the Flinders work remains at prototype stage in the lab.

ESS News and pv magazine both reported the result on the same day, each citing the Angewandte Chemie International Edition paper by Shangxu Jiang, Zhipeng Pei, Yanlin Shi, Kai Zhang, Justin M. Chalker, Sara J. Fraser-Miller, Michelle L. Coote and Zhongfan Jia.