Preparation of La0.7Sr0.3CoO3-δ (LSC)@MnO2 core/shell nanorods as high-performance electrode materials for supercapacitors

Perovskite oxides have attracted significant attention as capacitor electrode materials owing to their unique physical and electronic properties. In this paper, a novel La 0.7 Sr 0.3 CoO 3-δ (LSC)@MnO 2 core–shell nanorod was synthesized by controlled electrospinning combined with hydrothermal synthesis. The LSC, as a typical perovskite-type material, with excellent stability and ion–electron double conductivity, can perfectly serve as conductive backbone. Grid-like MnO 2 nanosheets are grown on LSC to form a unique core/shell nanostructure, could effectively improve the electrochemical performance of MnO 2 . The grid-like MnO 2 nanosheets shell significantly increase the effective area over which the reaction may take place and reduce the ion/electron transmission distance, which is beneficial in that it shifts in ions and electrons, enhancing the electrochemical reaction kinetics thereof. LSC@MnO 2 core/shell nanorods demonstrated good electrochemical performance with high capacitance (570 F g −1 at 1 A g −1 ), and revealed excellent cycling stability (capacitance retention remains at 97.2% after 5000 cycles). The asymmetric supercapacitor device (LSC@MnO 2 //AC) displayed a desirable energy density of 37.6 W h kg −1 at 375 W kg −1 , and still remains at 23.3 W h kg −1 at a high power density of 7489.3 W kg −1 , indicating that the LSC@MnO 2 nanorods are an outstanding pseudo-capacitive electrode material, with significant potential for application in high-performance supercapacitors.