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

The La 1.3 CaMg 0.7 Ni 9 alloy was modified with various metal oxides ( Fe 2 O 3 , TiO 2 , Cr 2 O 3 , ZnO), and the effects of metal oxides addition on the electrochemical properties of the La 1.3 CaMg 0.7 Ni 9 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% TiO 2 , Cr 2 O 3 , and ZnO, while the cyclic stability does not change except for addition of Fe 2 O 3 . The low-temperature property is enhanced more obviously by addition of TiO 2 , Cr 2 O 3 , 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.