Keywords: fuel cell, energy storage
Summary:A fuel cell combined with an electrolyzer offers the potential to provide storage for large amounts of energy at a lower cost than batteries. These reversible fuel cell systems are beginning to be commercialized in micro-grid applications. However, in conventional reversible fuel cell energy storage systems, the fuel cell and electrolyzer do not operate simultaneously. Significant system cost savings could be achieved if a single cell stack could operate as both an electrolysis stack and a fuel cell stack. The challenge with this “unitized” approach is degradation of conventional catalysts in the oxygen electrode during voltage cycling, and optimization of the electrodes for both fuel cell and electrolysis operation. While precious metal-based unitized PEM cell technology exists, it requires high loadings of precious metal in the electrodes, rendering it cost-prohibitive for commercial grid applications. pH Matter has developed a unitized reversible alkaline-based cell technology that does not require precious metal electrodes. In this presentation, progress towards demonstration of the promising technology in a reversible fuel cell system for grid energy storage will be reviewed.