Rapid hydrogen charging on metal hydride negative electrode of Fuel Cell/Battery (FCB) systems

The characteristics of rapid gaseous H2 charging/electrochemical discharging of the metal hydride negative electrode were investigated for the application in Fuel Cell/Battery (FCB) systems. They were evaluated with the H2 gas absorption, followed by the subsequent electrochemical discharging in the electrolyte solution (6M KOH). Then, the cyclability of charge–discharge was also examined. It was observed that more than 70% of the theoretical capacity was charged within 10 min with 0.3 MPa and 0.5 MPa of the initial H2 pressures. The electrochemical discharge curve showed that more than 86% of the absorbed H2 was discharged. Furthermore, the cycled charge–discharge process indicated that the H2 gas charge and electrochemical discharge process is an effective way to rapidly charge and activate the metal hydride without degeneration.