Electrochemical hydrogen charge and discharge properties of La0.1Sr0.9Co1−yFeyO3−δ (y = 0, 0.2, 1) electrodes in alkaline electrolyte solution

In this work, we studied the hydrogen storage properties of some La0.1Sr0.9Co1−yFeyO3−δ perovskite oxides for the application in Ni–H batteries. Sr-doped La0.1Sr0.9FeO3−δ (LSF), La0.1Sr0.9CoO3−δ (LSC) and La0.1Sr0.9Co0.8Fe0.2O3−δ (LSCF) oxides were synthesized by conventional solid state method and were selected as anode materials for Ni–H battery. Their electrochemical hydrogen charge/discharge properties of oxide electrodes were investigated and exchange current density and proton diffusivity were calculated using linear polarization measurement and the potential-step method, respectively. X-ray photoelectron spectroscopy (XPS) analysis was used to show the changes in oxidation states of transition metal ions during charging/discharging process. The proton diffusion rates for LSF, LSC and LSCF were 6.73 × 10−17, 1.45 × 10−16 and 2.16 × 10−16 cm2 s−1, respectively.