Flexible synthesis of high-performance electrode materials of N-doped carbon coating MnO nanowires for supercapacitors

The MnO/C composites were obtained by co-precipitation method, which used Mn3O4 nanomaterials as precursors and dopamine solution after ultrasonic mixing and calcination under N-2 atmosphere at different temperatures. By studying the difference of MnO/C nanomaterials formed at different temperatures, it was found that with the increase of calcination temperature, the materials appear obvious agglomeration. The optimal calcination temperature is 400 degrees C, and the resulting MnO/C is a uniformly dispersed slender nanowire structure. The specific capacitance of MnO/C nanowires can reach 356 F g(-1) at 1 A g(-1). In the meantime, the initial capacitance of MnO/C nanowires remains 106% after 5000 cycles. Moreover, the asymmetric supercapacitor was installed, which displays a tremendous energy density of 30.944 Wh kg(-1) along with a high power density of 10 kW kg(-1). The composite material reveals a promising prospect in the application of supercapacitors.