A Solid-State Metal Hydride/Oxygen Cell using La0.78Ce0.22Ni3.73Mn0.30Al0.17Fe0.50Co0.30 in the Anodeand Nafion as Electrolyte

Abstract

Abstract.A solid polymer electrolyte metal hydride (MH)/oxygen cell using La 0.78 Ce 0.22 Ni 3.73 Mn 0.30 Al 0.17 Fe 0.50 Co 0.30 in the anode and Nafion as electrolyte is described and investigated experimentally. In this work, the discharge performances of the cell are compared in two charging ways, namely, electrochemical and gas-solid hydrogenation. The specific discharge capacityby gas-solid hydrogenation method is about 59.3mAh·g -1 , while almost few specific discharge capacityis obtained by electrochemical method in this work. The cell is characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. And the ex-situ XRD results of the cell charged by gas-solid hydrogenation method show that an electrochemical reaction between hydrogen and oxygen does happen, and little observable side reaction occurs. Moreover, the stability of the MH electrode depending on various relative humidity is investigated. The results indicate that solid-state MH/O 2 cell using Nafion as electrolyte is technically feasible, while the control of the water content during charge/discharge processes and the catalyst loading must be the key points. More than that, further researches are still required to enhance both charge/discharge capacity and reversibility.