Abstract Scope |
High entropy oxides (HEO) are well known for their ability to contain many principal elements, while still forming a single-phase solid solution structure. Interestingly, many HEOs exhibit reversible phase transformations. However, little attention has been paid to understanding these phase transformations and the resulting secondary phases in these material systems. Phase transformations are known to be a powerful lever for controlling microstructure and behavior. Here we explore the role of controllable secondary phases on the overall charge transport behavior in the (Co,Cu,Mg,Ni,Zn)1-xNaxO system. We find that heat treatment time, heat treatment temperature, and grain size influence the formation of secondary phases and in turn the electrical behavior. By investigating the interplay between phase state, microstructure, and charge transport in (Co,Cu,Mg,Ni,Zn)1-xNaxO, this study sheds light on the design and engineering of high entropy oxide materials for enhanced electrochemical performance. |