Sr2+-doped La1-xSrx(Co0.2Mn0.2Fe0.2Ni0.2Cu0.2)O3 high-entropy perovskite oxides as supercapacitor electrodes

High-entropy perovskite oxides (HEPOs) have emerged as promising electrode materials for supercapacitors. In this study, we successfully synthesized a series of HEPOs La 1- x Sr x (Co 0.2 Mn 0.2 Fe 0.2 Ni 0.2 Cu 0.2 )O 3 , using the sol–gel method. We thoroughly investigated the impact of Sr doping on the electrochemical properties of HEPO materials. Our findings indicate that the incorporation of a small amount of Sr enhances ionic conductivity and promotes the formation of oxygen vacancies and ionic vacancies within the crystal structure. The incorporation of Sr significantly improves the electrochemical performance of HEPOs materials. La 0.9 Sr 0.1 (Co 0.2 Mn 0.2 Fe 0.2 Ni 0.2 Cu 0.2 )O 3 electrode exhibits a maximum specific capacitance of 204.33 F/g at a scan rate of 2 mV/s, a significant increase compared to the undoped La(Co 0.2 Mn 0.2 Fe 0.2 Ni 0.2 Cu 0.2 )O 3 sample. Furthermore, La 0.9 Sr 0.1 (Co 0.2 Mn 0.2 Fe 0.2 Ni 0.2 Cu 0.2 )O 3 electrode exhibits excellent rate performance, maintaining 74% of its capacity when the current density was increased from 1 to 5 A/g. It also exhibits good cycling stability, with nearly no attenuation after 1000 cycles. Therefore, these results underscore the potential of our synthesized high-entropy perovskite oxides as electrode materials for supercapacitors applications.