A team from the University of Flinders in Australia has developed a zinc-iodine aqueous battery capable of exceeding 60,000 charge and discharge cycles in the laboratory. In one of the tested configurations, the cell could be charged in about three minutes while maintaining around 150 mAh/g, figures that stand out for their longevity, though they are still part of an experimental technology rather than a commercial battery.
The key features of the zinc-iodine battery in 20 seconds
- The experimental cell surpasses 60,000 cycles under specific laboratory conditions.
- It can complete a charge in approximately three minutes during the longest lifespan test.
- Uses a polymer based on cyclodextrins to control iodine compounds that degrade the battery.
- Its aqueous electrolyte avoids the use of flammable organic solvents typical in lithium-ion batteries.
The work was published on August 13, 2026, in Angewandte Chemie International Edition by researchers led by Shangxu Jiang and Zhipeng Pei. The University of Flinders also confirmed that the team is collaborating with industry to create a prototyping platform to advance toward larger systems.
This research is especially relevant for stationary energy storage applications. In grid-connected systems, solar installations, or wind farms, factors like safety, material costs, and cycle count can be as important as maximizing energy density.
60,000 cycles, but understanding what that number really means
Talking about a battery that lasts 60,000 cycles can easily lead to the assumption of a battery for electric cars or smartphones that practically never needs replacement. The study does not demonstrate that.
The researchers worked with experimental cells and various charging conditions.
In one case, the battery operated at around 1.3 to 1.4 volts, achieved approximately 200 mAh/g, and could complete over 8,000 cycles when fully charged in about seven minutes.
Later, the team increased the charging speed. With a full charge in roughly three minutes, capacity was around 150 mAh/g, yet the cell managed to exceed 60,000 cycles.
This highlights an important point: maximum capacity, longevity, and faster charging do not necessarily occur simultaneously under the same conditions.
Additionally, the scientific paper reports capacities up to 205 mAh/g via two-electron storage (2e) and 365 mAh/g via a four-electron mechanism (4e). The degradation rates indicated by the researchers range from 0.0001% to 0.0003% per cycle, depending on configuration.
Therefore, describing it directly as an “eternal” battery would be an exaggeration. What has been demonstrated is that experimental zinc-iodine chemistry has achieved stability over tens of thousands of cycles under controlled conditions, which is especially significant for a developing technology.
A «molecular cage» to prevent iodine escape
The achieved longevity is closely related to the solution adopted to address one of the known issues in aqueous zinc-iodine batteries.
During operation, polypoid species can form and migrate from the cathode to other parts of the cell.
This behavior, commonly called the shuttle effect, causes active material loss, self-discharge, and a gradual degradation of performance.
Researchers have attempted to solve this through a chemistrial host-guest strategy.
They developed a polycyclodextrin network (polyCD). Cyclodextrins are oligosaccharides with molecular structures featuring a cavity that can be derived from starch.
Simply put, they act as tiny cages capable of housing specific molecules.
The key is to find the right balance: iodine compounds must be retained strongly enough to prevent free migration within the cell, but not so much that they block the electrochemical reactions necessary for energy storage and release.
Experiments and simulations by the team indicate that β-cyclodextrin is particularly suitable due to the size of its internal cavity and its moderate affinity for polyhalide anions.
An overly weak bond would not effectively mitigate the shuttle effect, while an excessively strong one could hinder battery operation.
The research also observed differences when incorporating other halides. Adding bromide ions (Br−) allowed for a more effective binding with certain positively charged iodine species and reduced their hydrolysis compared to using chloride. This aspect of chemistry is crucial for achieving four-electron storage and higher capacities studied by the group.
Water also impacts the battery’s safety
Another notable feature is the word “aqueous.”
Many commercial lithium-ion batteries use flammable organic electrolytes. If a cell suffers damage, internal defects, or excessive heat, thermal runaway can occur—a risk that necessitates numerous safety mechanisms in vehicles, electronics, and large battery installations.
Aqueous batteries use an electrolyte mainly based on water.
This can offer a safety advantage over certain lithium-ion chemistries with flammable organic electrolytes, especially for stationary systems designed to store large amounts of electricity.
However, this does not mean an aqueous battery is automatically safe or “explosion-proof.” A commercial battery incorporates materials, electrical connections, and power systems whose risks must be assessed during development and certification.
Material choice is also attractive from another perspective.
The polymer used by the researchers is derived from cost-effective, biodegradable oligosaccharides, while zinc is a widely used industrial element with a supply chain distinct from lithium.
Australia has a particular interest in this chemistry. According to the researchers, the country holds approximately between 20% and 28% of the world’s known zinc reserves and resources, which could support an industrial chain linked to energy storage based on this metal.
The initial goal is energy storage, not replacing lithium in phones
The next challenge will be much more difficult than achieving promising results in a laboratory cell: scaling up the technology.
A chemistry that works well in small experimental cells does not guarantee maintaining capacity, charge rate, efficiency, cost, or longevity when transformed into modules with hundreds or thousands of cells.
Factors like system-level energy density, zinc anode stability, operating temperature, self-discharge, industrial manufacturing, recycling, and cost per kilowatt-hour stored also need to be studied.
For now, the researchers see one of their main opportunities in large-scale energy storage.
Associate Professor Zhongfan Jia from Flinders University explains that aqueous zinc-iodine batteries are shaping up as a potential alternative for such applications and confirms that the team is working with industry to establish a prototyping platform.
This is precisely where 60,000 cycles can be particularly appealing.
An installation connected to solar or wind generation can repeatedly charge and discharge its batteries over years. If a technology can combine a long lifespan, relatively low-cost materials, and less reliance on flammable electrolytes, it could find its niche—even if it does not match all the advanced features of top lithium batteries.
Flinders’ research still needs to prove that these advantages will survive the transition from laboratory to commercial systems. The 60,000 cycles and three-minute charge are actual experimental results, but they do not yet equate to an industrial battery with such performance.
That will be the next test for this promising chemistry.
Frequently Asked Questions
Is it true that this battery lasts 60,000 cycles?
Yes. The researchers managed to surpass 60,000 cycles in a specific experimental setup, with a capacity close to 150 mAh/g and a charge time of about three minutes. However, this does not mean a commercial battery with these specs already exists.
Can the battery really be charged in three minutes?
One tested configuration could complete charging in approximately three minutes. Another achieved around 200 mAh/g over more than 8,000 cycles with charging times close to seven minutes.
Could it replace lithium batteries?
It’s too early to say. The technology is still in the experimental phase, and the team is working on prototyping. One potential application is for stationary energy storage systems.
Why can it last so many cycles?
The cathode uses a polymer based on β-cyclodextrin that acts as a molecular cage for iodine compounds, reducing their migration within the cell and the gradual loss of active material.
