Comparison of Acid and Alkaline Hydrogen-Bromine Fuel Cell Systems

Abstract

The hydrogen bromine (H2-Br2) fuel cell system is an attractive system for electrical energy storage because of its high round-trip conversion efficiency, high power density capability, and anticipated low costs. The hydrogen-bromine fuel cell system can be operated in the acid or alkaline modes. The alkaline H2-Br2 fuel cell was evaluated because of its advantages over the acid system such as higher cell potential and low cost catalyst for the hydrogen evolution and oxidation reactions. A fuel cell was assembled to validate the feasibility of the alkaline system and evaluate its performance. The results confirmed that an alkaline H2-Br2 fuel cell has higher cell voltage and fast electrode reaction kinetics like in the acid system. However, the performance is currently limited by the low ionic conductivity of the membranes which is attributed to the slow diffusivity of the K+ ions.