Research on the doping effects on the microstructure and electrochemical hydrogen storage properties of BaCeO3 with Ni, Mn, Li and Y ions

The BaCe 0.98 M 0.02 O 3 (M = Ce, Y, Li, Mn, Ni) solid solution was successfully synthesized via a combustion method. The microstructure and spectra characteristics were analyzed systemically. The X-ray diffraction (XRD) results showed that the structures of the BaCeO 3 -based materials kept cubic perovskite single-phase structure. The findings from the Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) analyses revealed that the doped samples exhibited smaller grain sizes and the doped elements are distributed uniformly. The spectral analyses revealed that the doped samples contain higher contents of oxygen vacancies in the lattices. The electrochemical hydrogen storage characteristics of the samples demonstrated that the doped samples possess greater discharge capacities compared to pure BaCeO 3 . The Y-doped sample demonstrated superior electrochemical performance, delivering a remarkable specific capacity of 377 mA h/g (hydrogen content of 4.56 %) with excellent capacity retention of 371 mA h/g after 50 cycles. Moreover, the incorporation of Y ions not only significantly enhanced the rate capability but also effectively suppressed the self-discharge behavior. The hydrogen storage mechanism was speculated. The characteristics of hydrogen storage are significantly influenced by the lattice parameters, the concentration of oxygen vacancies and defects, as well as the nature of the doped ions.