Innovative low-critical raw materials and medium-entropy perovskite for intermediate temperature solid oxide electrochemical cells

Abstract

Ceramic proton conductive electrolytes are promising materials for reducing the operating temperatures of solid oxide cells. It is desirable to achieve such a target because, as a result, durability, cost of materials, electrochemical reactions and flexibility of its use can be significantly enhanced. A medium-entropy perovskite with the stoichiometric formula Ba0.5Sr0.5Zr0.5Zn0.5O3 was studied in the present work using limited amounts of critical raw materials. According to the performed analysis, it is possible to achieve complete phase purity at 1300 °C. Based on dilatometric measurements, the material can undergo significant densification starting at 1200 °C; at about 1550 °C the produced perovskite melts and degrades simultaneously. One of the most effective characteristics of the pure phase is its ability to absorb moisture and the excellent stability to redox mechanism. This material's characteristic was confirmed by a series of thermochemical procedures and XRD analyses. As a result of electrochemical measurements carried out on 93% dense pellet consolidated at 1350 °C, the material has a much better conductivity and activation energy than BZY.