Design of SrZr0.1Mn0.4Mo0.4Y0.1O3-δ heterostructured with ZnO as electrolyte material: Structural, optical and electrochemical behavior at low temperatures

P-type semiconductor SrZr0.1Mn0.4Mo0.4Y0.1O3-delta (SZMMY) is for the first time composited with n-type ZnO to prepare a solid oxide electrolyte used in fuel cell operable at low temperature. Prepared nanocomposite elec-trolyte material is considered as a novel material owing to the results obtained in terms of improved ionic conductivity, power density, and current density at lower operational temperature. The material has been analyzed as well crystalline material with a dual-phase as confirmed by X-Ray Diffraction (XRD). The structural morphology of designed electrolyte materials was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), including high-resolution TEM (HR-TEM). The electrochemical impedance spectra (EIS) showed a remarkably lower charge transfer resistance than conventional electrolyte materials. Obtained results illustrated that ionic conductivity increased, which lead to the acceleration of the electrode reactions. Heterostructure nanocomposite SZMMY-ZnO is beneficial to attain a high ionic conductivity due to the suppression of electronic conduction through the p-n junction. The maximum power density was noted as 841 mW cm-2 at 550 degrees C with a maximum current density of 2287 mA cm-2. Based on optical properties through the p-n junction, the internal electronic current was blocked, which further reduced the short circuit problem in the heterostructure. In addition, the performance and lifetime test indicated good stability of the cell at 550 degrees C with a very small degradation loss. The present study suggests that the SZMMY-ZnO is a promising electrolyte for low-temperature-SOFCs development.

Automated summary

P-type semiconductor SrZr0.1Mn0.4Mo0.4Y0.1O3-delta (SZMMY) is composited with n-type ZnO to prepare a solid oxide electrolyte with improved properties for low-temperature fuel cells. The nanocomposite electrolyte material shows enhanced ionic conductivity, power density, and current density at lower temperatures. The structural analysis confirmed a dual-phase crystalline structure, and the electrochemical impedance spectra demonstrated lower charge transfer resistance. The heterostructure nanocomposite SZMMY-ZnO inhibits electronic conduction and achieves high ionic conductivity, resulting in improved fuel cell performance.