Nanosheet-assembled LaMnO3@NiCo2O4 nanoarchitecture growth on Ni foam for high power density supercapacitors

LaMnO3 is a promising candidate for used in supercapacitor because of its unique anion-based intercalation capacitive behavior. Its electrochemical performance, however, is still seriously limited by the intrinsically poor electrical conductivity and the exudation of Mn species during reversible intercalation. Herein, we demonstrate that the hybridization of LaMnO3 with NiCo2O4 to form hierarchical core-shell nanosheet-assembled architectures on Ni foam can efficiently suppress the leaching of Mn species and evidently improve the electronic conductivity, thus optimizing its physicochemical properties for supercapacitance. As expected, superior capacitive performance is achieved with ultrahigh specific capacity of 811 C g(-1) at 0.5 A g(-1), and the capacity still reached 555 C g(-1) even at the largest current density of 16 A g(-1) with a high rate capability of 68%. When assembled with activated carbon (AC) as an hybrid supercapacitor device, it delivers not only maximum energy density of 36.6 Wh.kg(-1) at a power density of 800W kg(-1) and ultrahigh power density of 25,600 W kg(-1) at an energy density of 19.4 Wh.kg(-1), but also robust cycling stability (up to 10,000 cycles), holding great potential for future energy storage devices. (C) 2019 Elsevier Ltd. All rights reserved.