Iodine batteries gain an extra charge-storage reaction in water
Researchers stabilized an additional iodine reaction in water-based laboratory batteries by changing the liquid that carries charge between electrodes. The electrolyte avoids concentrated halide salts. A single peer-reviewed study tested the approach in zinc–iodine and aluminium–iodine systems, while iodine losses and performance at higher electrode loading remain constraints.
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More charge from iodine
Researchers enabled an extra charge-storage reaction in water-based iodine batteries by redesigning the electrolyte, the liquid carrying charge between electrodes. Their single peer-reviewed study, published on November 11, reports reversible four-electron iodine conversion without the concentrated halide salts used in earlier approaches. The electrolyte controls the chemical surroundings of iodine at the electrode surface, where water can otherwise destabilize the reaction.[1]
A redesigned chemical environment
The team combined ions with molecules able to donate an electron pair, helping stabilize positively charged iodine intermediates. Tests covered zinc–iodine batteries and an aluminium–iodine system. The extra reaction doubles iodine's theoretical charge capacity to 422 milliampere-hours per gram, compared with 211 for the conventional reaction. That calculation applies to the active iodine material; the weight and other components of a complete battery remain outside that figure.[1]
Laboratory cells and cycling
One laboratory condition preserved 96 per cent of capacity through 1,000 charging cycles; another retained 94 per cent through 2,000 cycles at a different current. The team also demonstrated a larger pouch-format cell. Iodine losses and charge efficiency remained problems as more active material was loaded onto electrodes. The results describe experimental battery chemistry, with performance still dependent on cell design and operating conditions.[1]
