Effects of metal oxides addition on the performance of La1.3CaMg0.7Ni9 hydrogen storage alloy

The La1.3CaMg0.7Ni9 alloy was modified with various metal oxides (Fe2O3, TiO2, Cr2O3, ZnO), and the effects of metal oxides addition on the electrochemical properties of the La1.3CaMg0.7Ni9 hydrogen storage alloy were investigated. The catalytic effects of metal oxides are found. Not only the discharge capacity but also the high-rate dischargeability (HRD) is improved by addition of 5 wt% TiO2, Cr2O3, and ZnO, while the cyclic stability does not change except for addition of Fe2O3. The low-temperature property is enhanced more obviously by addition of TiO2, Cr2O3, and ZnO. The electrochemical kinetics is also measured by the linear polarization and electrochemical impedance spectroscopy (EIS). In addition, the hydrogen absorption kinetic behavior is measured by gas-solid reaction.