Green and environmental-friendly method to synthesize template free nano grass-flower hierarchical manganese dioxide for high performance supercapacitor

Abstract

In this article, a simple and environmentally benign one-pot hydrothermal strategy has been developed for the synthesis of nano grass-flower hierarchical manganese dioxide without the use of either templets or acid. Because of synergistic effects of nano grass and nano flower, the nano grass-flower hierarchical structure exhibits specific capacitance of 230 F g−1 at the current density of 1.0 A g−1 and acquires outstanding cycling stability after 10000 cycles with specific capacitance retention of 81%. The samples were analyzed by XRD and FTIR while SEM and TEM were used to confirm the morphology of MnO2. For the evaluation of the electrochemical performance of prepared samples, cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) cycling tests were conducted. Further, an aqueous asymmetrical supercapacitor device (nano grass-flower MnO2//AC and nano grass-MnO2//AC) constructed, nano grass-flower MnO2//AC illustrated an energy density of 30 Wh Kg−1 with a maximum power density of 18000 W kg−1. In addition, the device nano grass-flower MnO2//AC. Finally, this work will provide a new strategy to synthesize worthwhile nanostructures that reveal potential applications in energy storage electrodes.