Development of Asymmetric Electrodes of Robust MoS₂/rGO Heterostructures with MnO₂ Nanohybrid Composites for Cylindrical Type Energy Storage Devices

Abstract

In the current era, researchers are focusing on effective electrodes to enhance energy storage devices including high energy and power density. Among them, two-dimensional (2D) materials play a crucial role in supercapacitors and batteries due to their enormous electrochemical properties. Here, MnO 2 nanorods are uniformly decorated above the novel surface of MoS 2 /rGO heterostructure electrode materials for hybrid supercapacitors via a facile hydrothermal approach. The physical and chemical properties of the prepared pure, binary, and ternary nanocomposites are investigated by suitable characterization techniques. The 2D heterostructure of MoS 2 /rGO offers an enlarged surface area, continuous network pathways, improved electronic conductivity, and electro-active sites in the MnO 2 / MoS 2 /rGO nanohybrid composite electrode. Due to the dimensional structure and synergetic effect of MoS 2 /rGO, the MnO 2 nanohybrid composite attained a maximum specific capacitance of 1052.2 Fg −1 at 1 Ag −1 and the ternary composite delivered an extraordinary capacitance retention of 97.5% over the 10,000 cycles in 1 M of Na 2 SO 4 . Likewise, the prepared asymmetric supercapacitor devices of MnO 2 /MoS 2 /rGO//AC obtained a specific capacitance of 102 Fg −1 at 1 Ag −1 , as well as superior cyclic stability of 94% after 10,000 cycles, and the ASC device achieved a maximum energy density of 57.2 Wh kg −1 and a power density of 1.14 kW kg −1 in 2 V using a polymer gel electrolyte of PVA-Na 2 SO 4 solution. Moreover, a cylindrical-shaped ASC device was constructed, and the ability of the device was also tested via an LED system. The electrochemical attributes of two-dimensional MoS 2 and rGO nanosheets with MnO 2 nanorod nanocomposite electrodes become a superior electrochemical electrode material for the upcoming generation.