MnO2 Nanorods Embedded Reduced Graphene Oxide Nanocomposite with Ultrahigh Specific Capacitance and Excellent Cyclic Stability for High Performance Supercapacitors

Excellent cycling stability along with a high specific capacitance of the electrode material is the primary requirement for supercapacitor (SC) in recent years. Exceptionally simple and cost-effective solution process is employed for the first time to prepare alpha-MnO2/rGO composites, in which KMnO4 content varies from (2 mg, 4 mg, 6 mg and 8 mg). The morphological analysis showed that alpha-MnO2/rGO composites possess nanorod like morphology and were fully covered with rGO sheet. Among all composites, the sample with 6 mg content of KMnO4 denoted as alpha-MnO2/rGO composite (S-3) showed excellent supercapacitive performance with a specific capacitance of 720 F/g at a current density of 4 A g(-1) with excellent cycling stability of 93% after 2000 cycles. Furthermore, these nanocomposites showed excellent supercapacitive properties with specific capacitances of 720-498 F/g at the current density of 4 A g(-1) with cycling stabilities of 71%, 68% and 60%, respectively.