Fabrication of 3D Expanded Graphite-Based (MnO₂ Nanowalls and PANI Nanofibers) Hybrid as Bifunctional Material for High-Performance Supercapacitor and Sensor

A three-dimensional ribboned thermally expanded graphite (3D RTEG)-based (MnO 2 and PANI) bifunctional hybrid with layer-by-layer architecture has been obtained by one-step electrochemical intercalating electrodeposition of MnO 2 or PANI into 3D RTEG for supercapacitor and strain sensor applications. The outcomes demonstrate that large specific capacitance of 500 (∼4) and 700 F g −1 (∼6 F cm −2 ) are obtained for 3D RTEG-MnO 2 and RTEG-PANI, respectively. Moreover, both show high energy efficiencies of 65–70% and 75–78% for both, respectively. Furthermore, the assembled supercapacitor devices using the 3D RTEG-MnO 2 and RTEG-PANI electrodes show high energy densities of 50.12 (451.08) and 61.23 Wh kg −1 (551.07μWh cm −2 ) while maintaining high power densities of 15.26 (137.34) and 20.15 kW kg −1 (181.35 mW cm −2 ), respectively. Additionally, the 3D RTEG-PANI can be also used to assemble strain sensor for measuring weight, and the sensor displays excellent sensing performance. These magnetic outcomes indicate that the 3D RTEG-based composite can be served as potential material candidates for high performance supercapacitor and sensor. On the whole, it is worth noting that the facile and cost-effective procedure for synthesis 3D RTEG-based hybrid, can encourage researchers to synthesize different kinds of controllable RTEG-based hybrid with higher electrochemical and sensor performance.