Low temperature synthesis of MnO2 nanostructures for supercapacitor application

Herein, we are reporting a facile and novel TEA-ethoxylate assisted low temperature hydrothermal route for synthesis of stable nanostructured MnO2 and their application as an electrode material in supercapacitor. The synthesis was accomplished at two different reaction temperatures viz. 60 °C and 80 °C. The synthesized samples were characterized by various physicochemical characterization techniques viz. XRD, FESEM, FTIR and BET-BJH surface area analysis etc. The morphological study of the as-synthesized MnO2 samples revealed the mixed morphology consisting of nanorod and nanocrystals. The electrochemical studies revealed that the sample prepared at 80 °C exhibits superior electrochemical behavior in 1 mol L−1 Na2SO4 liquid electrolyte solution and demonstrated high specific capacitance of ~348.2 Fg−1 at a current density of 0.1 mAcm−2 and energy density of 43.3 WhKg−1. Further, this electrode showed high rate capability of 89% after 2000 cycles. The electrochemical impedance spectroscopic investigations revealed the low equivalent series resistance for MnO2 electrode. This work represents the promising performance of the nanostructured MnO2 electrode for high energy density supercapacitor application. © 2020