Alkaline Hydrogen-Iodine Reversible Fuel Cell

We have considered the acid-based H₂-I₂ fuel cell along with the acid-based H₂-Br₂ fuel cell as potential systems for electrical energy storage. However, we decided not to pursue the H₂-I₂ system because of its low cell open circuit potential (0.54V), even though the HI-I₂ environment is more benign than the HBr-Br₂ environment.  Recently, we found that by operating the hydrogen reactions in an alkaline medium we could shift the electrode standard reduction potential from 0V to -0.83V which combined with the bromine electrode standard reduction potential of 1.09V increases the cell potential of an alkaline H₂-Br₂ fuel cell from 1.09V to 1.92V [1].  This 0.83V shift in the hydrogen electrode potential motivated us to take another look at the alkaline H₂-I₂ system because of the higher cell potential (1.34V). See Figure 1. This presentation will discuss the alkaline H₂-I₂ system, its advantages and disadvantages, and recent development by our group at the University of Kansas.

Reference:

T.V. Nguyen, V. Yarlagadda, G. Lin, G. Weng, C.-Y.V. Li, and K.-Y Chan, “Comparison of Acid and Alkaline Hydrogen-Bromine Fuel Cell Systems,” ECS Transactions, 58, No. 37, 29-35 (2014).

Acknowledgements

This work was funded by the National Science Foundation under Grant No. EFRI-1038234.