Symmetric Electrochemical Supercapacitors Based on Electrodes of Graphene Nanoribbons/Iron-Doped Lanthanum-Strontium-Manganese Based Perovskite Oxides

Abstract

The dramatic increase in the world population and industrialization have resulted in unprecedented levels of humanity's hunger for energy. The total global energy production has increased from 23 in 1900 to 548 Exajoules (1018 J = EJ) in 2016.1 A significant contribution of the internment renewable energy resources to the energy production before the mid of this century becomes a necessity to significantly reduce fossil fuel usage and hence limit global warming.1 This creates a great incentive to identify the best ways to store energy when it is not needed.Supercapacitors have gained significant attention due to their fast charging/discharging speed, high power density, and long-term cycling stability in contrast to traditional batteries.2 In recent years, perovskites and graphene nanoribbons have been significantly considered promising materials for electrochemical energy storage. The graphene-based materials have a highly tunable surface area, outstanding electrical conductivity, good chemical stability, and excellent mechanical behavior.3 While the perovskite materials provide the possibility of both anionic and cationic storage mechanisms.4 This presentation reports the in situ preparation of iron-dopped lanthanum-strontium-manganese-based perovskite oxides (La0.7Sr0.3MnxFe1-xO3-δ, LSMFO) in the presence of graphene nanoribbons (GNRs), and the evaluation of the supercapacitive behavior of the synthesized composites. The physical/chemical structure of LSMFO was evaluated using XRD, TEM, FT-IR, Raman spectroscopy, EDS, BET, and XPS. Integrating the perovskite materials that possess redox reaction ability with graphene nanoribbons that exhibit good electronic properties is found to improve the supercapacitor performance in comparison to the single components. The symmetric supercapacitor devices based on LSMFO/GNRs showed good stability (capacitive retention of 95% over 10,000 cycles at a higher current density of 10 A g-1), a wide potential window (up to 1.7 V), and a relatively high capacitance. The best composite with optimum LSMFO:GNRs ratio that shows the highest supercapacitance is identified and explained in correlation with its surface chemical structure. References G. A. Jones and K. J. Warner, Energy Policy, 93, 206–212 (2016).S. Ghosh, K. Anbalagan, U. N. Kumar, T. Thomas, and G. R. Rao, Applied Materials Today, 21, 100872 (2020).O. D. Salahdin et al., Appl. Phys. A, 128, 703 (2022).B.-M. Kim et al., Sci Rep, 12, 10043 (2022).