Three-dimensional nitrogen-doped graphene wrapped LaMnO3 nanocomposites as high-performance supercapacitor electrodes

Abstract

In order to improve the electrochemical properties of LaMnO3 perovskite (LMO) materials for supercapacitor applications, different amount of nitrogen-doped reduced graphene oxide (N-rGO) from 25 to 75 wt % has been incorporated with LMO to form nanocomposite materials. These three-dimensional structures are assembled through electrostatic attraction of the positive charged N-rGO and the negative charged LMO. The amount of N-rGO has a significant effect on the properties of the composite materials. Microscopic investigations confirm that LMO particles are wrapped by N-rGO sheets, and with the increase of N-rGO content, the dispersion of LMO particles in graphene matrix is enhanced. Electrochemical characterizations reveal that the specific capacitance of the nanocomposites has been dramatically improved. Compared with pristine graphene and LMO, the sample with a lower amount of N-rGO (25%) exhibited the highest specific capacitance (687 Fg−1 at 5 mVs−1) and the longest stability (79% retention after 2000 cycle at 10 Ag−1) among other composite materials. The superior capacitive properties make LMO/N-rGO nanocomposites stand out as a promising candidate for supercapacitor applications.