Synergetic effect on enhanced electrochemical properties of MnO2 nanorods on g-C3N4/rGO nanosheet ternary composites for pouch-type flexible asymmetric supercapattery device
Rajesh Kumar, R. Thangappan
Abstract
In this work, one-dimensional MnO 2 nanorods are distributed evenly over two-dimensional g-C 3 N 4 /rGO nanosheets using a simple hydrothermal approach. The structure, functional group, morphologies, elemental analyses and surface area of prepared samples have been investigated. Moreover, the electrochemical performance of MnO 2 /g-C 3 N 4 /rGO in 1 M Na 2 SO 4 aqueous electrolyte solution was tested using cyclic voltammetry (CV), galvanostatic charge and discharge (GCD), electrochemical impedance spectroscopy (EIS) and capacitance retention. The MnO 2 /g-C 3 N 4 /rGO material has superior electrochemical performance than pure and binary electrode materials due to the high surface area of ternary composite (469.26 m 2 /g) compared to pure (38.083 m 2 /g). The ternary MnO 2 /g-C 3 N 4 /rGO electrode obtained the high specific capacitance of 716.6 Fg −1 at 1 Ag −1 and kept 97 % capacitance retention after 10,000 cycles at a current density of 10 Ag −1 . Since the synergistic effects of MnO 2 and g-C 3 N 4 /rGO improve electrochemical performance, the ternary composite is an excellent option for high-performance supercapacitors . Moreover, the pouch-type supercapattery device was assembled using MnO 2 /g-C 3 N 4 /rGO and activated carbon electrodes. The supercapattery device exhibits a maximum specific capacitance of 108.5 Fg −1 with 91.5 % capacitance retention after 10,000 cycles at a high current density of 10 Ag −1 . The device achieved a high energy density of 48.6 Wh kg −1 at a power density of 899.9 W kg −1 in the operating potential value of 0–1.8 V. The fabricated supercapattery device was tested for real practical application by charging 30 s and attained a self-discharging time of 5 min.