Inactive Al^(3+)-doped La(CoCrFeMnNiAl_(x))_(1/(5+x))O_(3)high-entropy perovskite oxides as high performance supercapacitor electrodes

A series of high-entropy perovskite oxides(HEPOs)La(CoCrFeMnNiAl_(x))_(1/(5+x))O_(3-δ)(x=0.4,0.5,0.6,and 0.7)have been synthesized by coprecipitation method combined with calcination process and explored as electrodes for supercapacitors.The crystal structure,microstructure,and elemental composition of HEPOs were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and energy-dispersive X-ray spectroscopy(EDS)in detail.The electrochemical properties of HEPOs as supercapacitor electrodes were elucidated.The specific capacitances of HEPOs(x=0.4,0.5,0.6,and 0.7)are 281.84,353.65,325.60,and 259.30 F/g at the current density of 1 A/g,respectively.After 2000 cycles,the specific capacitances of HEPOs(x=0.4,0.5,0.6,and 0.7)remain 85.01%,88.61%,86.37%,and 91.25%,respectively.Such outstanding electrochemical properties can be attributed to the entropy-stabilized structure caused by mixed six cations in B-site and the Al^(3+)-doping suppressing active ion aggregation during charge-discharge process.This research highlights the potential of HEPOs as electrodes for supercapacitors.