Supercapacitor devices based as SILAR synthesized ytterbium sulfide @ graphene oxide nanocomposite flexible thin film electrodes

Abstract

• For first time Yb 2 S 3 , GO and GO/Yb 2 S 3 composite films are prepared by SILAR method. • The GO/Yb 2 S 3 composite thin film showed maximum Cs of 376 Fg −1 at 5 mV s −1 scan rate. • The FSS-SSC device showed Cs 58F g −1 , E. D. 23 Wh kg −1 and P. D. 0.43 kW kg −1. • The FSS-ASC device showed Cs 92F g −1 , E. D. 42 Wh kg −1 and P. D. 0.84 kW kg −1. • Glowing of 211 red LEDs panel showed the practical application of both devices. Ytterbium sulfide (Yb 2 S 3 ), graphene oxide (GO), and graphene oxide/ytterbium sulfide (GO/Yb 2 S 3 ) composite thin films were synthesized by binder-free successive ionic layer adsorption and reaction (SILAR) method. Formation of Yb 2 S 3 , GO and GO/Yb 2 S 3 composite thin films was confirmed by XRD and XPS techniques. Surface morphology and particle size of these films were observed through FE-SEM and TEM analyses. All thin films showed hydrophilic nature. The Yb 2 S 3 , GO and GO/Yb 2 S 3 composite thin films exhibited the maximum specific capacitance of 181, 193 and 376 F g −1 , respectively in 1 M Na 2 SO 4 electrolyte at scan rate of 5 mV s −1 . The flexible solid state supercapacitor (FSS-SSC) symmetric device was fabricated with GO/Yb 2 S 3 composite electrodes as an anode and a cathode and a flexible solid state asymmetric supercapacitor (FSS-ASC) device were fabricated with GO/Yb 2 S 3 as an anode and MnO 2 as a cathode electrode with the PVA-Na 2 SO 4 gel electrolyte. The FSS-SSC device showed specific capacitance 58 F g −1 , energy density 23 Wh kg −1 and power density 0.43 kW kg −1 . The FSS-ASC device showed specific capacitance 92 F g −1 , energy density 42 Wh kg −1 and power density 0.84 kW kg −1 . Both FSS-SSC and FSS-ASC devices showed coulombic efficiency of 88 and 79% for 10,000 GCD cycles, respectively. The FSS-ASC device showed better performance than the FSS-SSC device. The FSS-ASC device showed better performance than the FSS-SSC device.