Researchers report a zinc-iodine battery combining rapid charging with exceptional cycle life, potentially offering safer, lower-cost energy storage for large-scale applications and renewable energy integration.
Flinders University researchers have developed a rechargeable aqueous zinc-iodine battery that the article says can retain performance for more than 60,000 charge-discharge cycles and recharge in about three minutes. The work is presented as a potential alternative to lithium-ion technology for large-scale energy storage.
The battery uses a water-based electrolyte, giving it advantages including lower fire risk and the potential for lower costs. However, zinc-iodine systems face a major technical problem known as the “shuttle effect”. Polyiodide species can move through the battery separator, causing performance to deteriorate over time.
The researchers addressed this problem by creating a host material based on cyclodextrin, a biodegradable polymer derived from starch. According to the article, the material can trap and release polyiodides, helping to control their movement and reduce unwanted reactions inside the battery.
The approach is significant because the researchers say zinc ions move relatively slowly through electrodes, which can make rapid charging and discharging difficult. Their design instead controls when different ions participate in the battery reaction. Zinc ions enter the electrode first at higher voltages, while smaller protons are stored later as the voltage falls. This sequential storage allows both charge carriers to contribute without interfering with zinc-ion storage.
Testing reportedly showed stable operation through rapid charge-discharge cycles, while the battery retained its performance over an extended period. The researchers also investigated the storage and release of both zinc ions and protons, supporting their approach to improving energy storage.
The article positions the technology primarily for large-scale energy storage, where safety, durability, charging speed and sustainable materials are important. Zinc’s abundance is also highlighted as an advantage, although further development and real-world testing will be needed before the technology can compete commercially with established battery systems.
