Facile ultrasound assisted in-situ synthesis of novel redox-active ferrocenyl-based nanocomposite: Applicable to energy storage

Organometallic compounds, especially ferrocene (Fc) due to their outstanding properties and excellent stable redox features, are appearing as ideal electrode materials for supercapacitors. In this research work, an ultrasonic solvent-substitution route was applied for the in situ synthesis of Fc nanophere on reduced graphene oxide (rGO) nanosheets. Then, the Fc-containing porous organic polymer (POP) was prepared by using a Schiff base reaction. Finally, we prepared a novel redox-active battery-type ternary rGO-Fc/POP nanocomposite via the self-assembly route to obtain a highly efficient Fc host for energy storage devices. Owing to the porous structure and the fast faradaic redox reactions of Fc units, the final nanocomposite shows a high specific capacity of 655.5 mAh g-1 at 2.5 A g-1 and 5 % capacity loss after 5000 cycles. A symmetric supercapacitor (SSC) based on rGO-Fc/POP as both anode and cathode can be acted on in a wide electrochemical window up to 1.8 V and attains excellent cycling performance (93 % remained after 3000 cycles). Also, our SSC cell exhibits high energy and power densities of 101.7 Wh kg-1 and 25.92 kW kg-1, respectively. This research provides a route to increase the electrochemical properties of redox-active battery-type electrode materials for high-performance SCs.