Flash sintering improves the densification and mechanical properties of high entropy oxides used in anodic applications

High entropy oxides (HEOs) have multi-cation disordered chemical structure that makes it suitable as anode for battery applications. (Mg 0.2 Ti 0.2 Zn 0.2 Cu 0.2 Fe 0.2 ) 3 O 4 has spinel structure with outstanding electrochemical performance because of its configurational entropy stabilized structure. However, its cyclability is poor because of its pulverization during charging-discharging cycles. Its hardness can be improved with better densification but sintering at higher temperatures (∼1200 °C) results in disintegration into different phases (phase separation). With the help of flash sintering, higher densification could be achieved with phase purity of spinel solid solution. The hardness of flash sintered specimens was found to be higher than that of conventionally sintered specimens of equivalent density, suggesting a better neck formation with flash sintering. The role of current density was investigated on density and hardness since porosity and strength both are important for anode applications. The uniform distribution of particles is confirmed by EDS analysis and the underlying mechanism for the ultrafast densification of the Reaction sintered HEOs has been discussed.