Australian researchers have made a breakthrough in sustainable energy storage with a new zinc-iodine battery design. This innovative battery uses dry electrodes, which are made by mixing active materials in powder form and compressing them into dense, self-sustaining electrodes. The team, led by Professor Shizhang Qiao from the University of Adelaide, added a small amount of 1,3,5-trioxane to the electrolyte, creating a flexible protective film on the zinc during charging. This film prevents the formation of dendrites, which are pointed structures that can cause short circuits.
Key Features and Advantages
The new zinc-iodine battery boasts several impressive features:
- Dry electrodes with a record active material loading of 100 mg/cm²
- Improved capacity retention: 88.6% after 750 cycles for pouch cells and 99.8% after 500 cycles for coin cells
- Higher energy density, potentially reaching 90 Wh/kg with further optimization
- Enhanced safety and reduced costs, making it ideal for large-scale energy storage
- Lower self-discharge rates due to reduced iodine leakage and unwanted reactions with the electrolyte
These advancements address historical issues with aqueous batteries, such as short lifespan and zinc instability. The dry electrode design and protective film formation during charging have significantly improved the battery’s performance and stability.
Potential Impact and Future Developments
The zinc-iodine battery has vast potential for renewable energy systems, grid-scale storage, and isolated microgrids, particularly in remote areas with limited infrastructure. Its safety, affordability, and durability make it an attractive alternative to traditional lithium-ion batteries. By reducing dependence on critical and potentially hazardous metals, this technology can contribute directly to global decarbonization efforts.
The research team is now working to optimize current collectors, reduce excess electrolyte, and explore other halogen chemistries. With these improvements, they aim to double the energy density to around 180 Wh/kg, bringing the technology closer to commercial viability. If successful, this innovation could become a cornerstone of sustainable energy storage.