Three-Dimensional Pompon-like MnO2/Graphene Hydrogel Composite for Supercapacitor

Micro-nanostructured pompon-like MnO2/graphene hydrogel (GH) composites with different mass ratios are prepared for supercapacitor electrodes. The morphology and structure are characterized by a range of electron microscopy and other techniques. The electrochemical performance of the prepared electrodes is investigated, and the MnO2/graphene hydrogel composite electrode with a MnO2 content of 50% delivers a specific capacitance of 445.7 F g(-1) at a current density of 0.5 A g(-1), and the specific capacitance remained 82.4% of the initial value after 5000 cycles. The high performance is ascribed to the 3D pompon-like micro-nanostructure of MnO2/graphene hydrogel that not only provides a good support to stabilize MnO2 but also facilitate the fast ion mobility and electron transfer. (C) 2016 Elsevier Ltd. All rights reserved.