Aqueous zinc–iodine batteries, featuring high energy density, safety, and cost-effectiveness, have been regarded as a promising energy storage system. Nevertheless, poor cycling stability and dissolution of iodine/polyiodide have greatly limited the development of zinc–iodine batteries.
The application of carbon fiber in zinc–iodine batteries provides a conversion area of iodine and places restrictions on the shuttle effect of intermediate products. It also has excellent conductivity which is necessary to improve the electrochemical efficiency.
Zinc-iodine batteries can be classified into zinc-iodine redox flow batteries (ZIRFBs) and static zinc-iodine batteries (SZIBs).
Rechargeable aqueous zinc iodine (ZnǀǀI 2) batteries have been promising energy storage technologies due to low-cost position and constitutional safety of zinc anode, iodine cathode and aqueous electrolytes.
Comparing the characteristics of alkali metal (Figure 1), aqueous zinc–iodine (Zn–I 2) battery has been studied owing to its high safety, low cost, environmentally friendly, and high performance. The Zn anode also has a high theoretical capacity of 820 mAh/g.
However, the iodine loading is below 2 mg cm −2 in most of the reported aqueous zinc-iodine batteries, resulting in a low practical energy density, which is still the key challenge in implementing their practical applications.