Preparation and Electrochemical Properties of High-Entropy Perovskite La_0.7Sr_0.3Co_0.4Fe_0.1Ni_0.4Cu_0.1O₃/RGO Composites

High-entropy perovskite oxides have attracted widespread attention in energy storage due to their unique high-entropy effects and multi-element synergy. However, they suffer from problems such as easy agglomeration of grains and low specific surface area, which limit their application in supercapacitor electrode materials. To enhance the pseudocapacitive properties of the high-entropy perovskite electrode materials, La_0.7Sr_0.3Co_0.4Fe_0.1Ni_0.4Cu_0.1O₃/Reduced Graphene Oxide(RGO) composites were prepared in this paper by the solvothermal method. The effects of RGO composite ratio on the microstructure and electrochemical properties of composite electrode materials were investigated. The phase results indicate that the high-entropy material La_0.7Sr_0.3Co_0.4Fe_0.1Ni_0.4Cu_0.1O₃ exhibits the cubic perovskite structure and is uniformly attached to the RGO sheets. The high-entropy composite material exhibits a higher specific surface area, which provides more active sites for redox reactions. Electrochemical tests reveal that the La_0.7Sr_0.3Co_0.4Fe_0.1Ni_0.4Cu_0.1O₃∶RGO(1∶2) composite exhibits optimal electrochemical performance. When the current density is 1 A·g⁻¹, the specific capacitance reaches 458.6 F·g⁻¹. which is much higher than that of the high-entropy perovskite La_0.7Sr_0.3Co_0.4Fe_0.1Ni_0.4Cu_0.1O₃ electrode material (242.8 F·g⁻¹). The La_0.7Sr_0.3Co_0.4Fe_0.1Ni_0.4Cu_0.1O₃ composite demonstrates favorable impedance characteristics, rate characteristics and long-term cycling stability. Therefore, high-entropy perovskite composites have broad application prospects in the field of supercapacitor energy storage.