Synthesis, Characterisation and Electrochemical Performance of Reduced Graphene Oxide–Metal Oxide Nanocomposite Electrodes for High-Energy Supercapacitor Applications

Author(s): Vikram Singh Chauhan, Arunabha Ghosh, Deepak Ranjan Sahoo

Affiliation: Department of Chemical Engineering, Biju Patnaik Institute of Technology, Rourkela, Odisha, India Department of Materials Engineering, Himachal Pradesh Institute of Engineering and Technology, Shimla, Himachal Pradesh, India

Page No: 1-8

Volume issue & Publishing Year: Volume 3, Issue 6, 2026/06/02

Journal: International Journal of Modern Engineering and Management | IJMEM

ISSN NO: 3048-8230

Download PDF Cite this article

Abstract:

Electrochemical double-layer capacitors and pseudocapacitors — collectively termed supercapacitors — occupy a critical niche in the energy storage landscape between conventional dielectric capacitors and rechargeable batteries, offering higher power density than batteries and higher energy density than capacitors. The primary limitation constraining supercapacitor deployment in electric vehicle regenerative braking systems and grid-scale pulse power applications is the insufficient energy density (typically 5–10 Wh/kg for carbon-based electrodes) relative to lithium-ion batteries (150–250 Wh/kg). Reduced graphene oxide (rGO), produced by chemical or thermal reduction of graphene oxide, provides a high-surface-area conducting scaffold (theoretical surface area 2630 m²/g) that supports pseudocapacitive metal oxide nanoparticles whose Faradaic redox reactions dramatically increase charge storage capacity beyond the pure electrical double-layer mechanism available to carbon-only electrodes. This study synthesises rGO/metal oxide nanocomposite electrodes incorporating MnO₂, NiO, and Co₃O₄ nanoparticles by hydrothermal co-deposition, comprehensively characterises them by XRD, FTIR, Raman spectroscopy, SEM-EDX, BET surface area analysis, and electrochemical techniques including cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS), and evaluates their cycling stability over 5000 charge-discharge cycles. The rGO/MnO₂ composite achieves the highest specific capacitance of 412 F/g at 1 A/g with energy density of 45.8 Wh/kg and power density of 0.31 kW/kg, retaining 87.4% capacitance after 5000 cycles. BET analysis confirms systematic increase in accessible surface area from 186 m²/g (neat rGO) to 312 m²/g (rGO/MnO₂). EIS reveals a charge transfer resistance of 1.2 Ω for rGO/MnO₂, confirming low interfacial impedance that underpins high rate capability.

Keywords:

supercapacitor, reduced graphene oxide, manganese dioxide, nickel oxide, cobalt oxide, hydrothermal synthesis, cyclic voltammetry, electrochemical impedance spectroscopy, energy density, cycling stability

Reference:

• [1] An, C., Zhang, Y., Guo, H., & Wang, Y. (2019). Metal oxide-based supercapacitors: progress and prospectives. Nanoscale Advances, 1(12), 4644-4658.

• [2] Chen, J., Sheng, K., Luo, P., Li, C., & Shi, G. (2012). Graphene hydrogels deposited in nickel foams for high-rate electrochemical capacitors. Advanced Materials, 24(33), 4569-4573.

• [3] Cheng, Y., Lu, S., Zhang, H., Varanasi, C. V., & Liu, J. (2012). Synergistic effects from graphene and carbon nanotubes enable flexible and robust electrodes for high-performance supercapacitors. Nano Letters, 12(8), 4206-4211.

• [4] Dubal, D. P., Ayyad, O., Ruiz, V., & Gomez-Romero, P. (2015). Hybrid energy storage: the merging of battery and supercapacitor chemistries. Chemical Society Reviews, 44(7), 1777-1790.

• [5] El-Kady, M. F., Strong, V., Dubin, S., & Kaner, R. B. (2012). Laser scribing of high-performance and flexible graphene-based electrochemical capacitors. Science, 335(6074), 1326-1330.

• [6] Huang, Y., Liang, J., & Chen, Y. (2012). An overview of the applications of graphene-based materials in supercapacitors. Small, 8(12), 1805-1834.

• [7] Kumar, R., Singh, R. K., Alaferdov, A. V., & Moshkalev, S. A. (2018). Rapid and controllable synthesis of Fe3O4 octahedral nanocrystals embedded-reduced graphene oxide using microwave irradiation for high-performance lithium-ion batteries. Electrochimica Acta, 281, 78-87.

• [8] Lee, J. W., Hall, A. S., Kim, J. D., & Mallouk, T. E. (2012). A facile and template-free hydrothermal synthesis of Mn3O4 nanorods on graphene sheets for supercapacitor electrodes with long cycle stability. Chemistry of Materials, 24(6), 1158-1164.

• [9] Nagaraju, G., Ko, Y. H., & Yu, J. S. (2015). Urchin-tipped gold nanorods on graphene with superior electrochemical performance as a flexible supercapacitor electrode. CrystEngComm, 17(11), 2238-2245.

• [10] Peng, X., Peng, L., Wu, C., & Xie, Y. (2014). Two dimensional nanomaterials for flexible supercapacitors. Chemical Society Reviews, 43(10), 3303-3323.

• [11] Rakhi, R. B., Chen, W., Cha, D., & Alshareef, H. N. (2012). Substrate dependent self-organization of mesoporous cobalt oxide nanowires with remarkable pseudocapacitance. Nano Letters, 12(5), 2559-2567.

• [12] Wang, G., Zhang, L., & Zhang, J. (2012). A review of electrode materials for electrochemical supercapacitors. Chemical Society Reviews, 41(2), 797-828.

• [13] Xia, H., Zhu, D., Fu, Y., & Wang, X. (2012). CoFe2O4–graphene nanocomposite as a high-capacity anode material for lithium-ion batteries. Electrochimica Acta, 83, 166-174.

• [14] Zhang, L. L., & Zhao, X. S. (2009). Carbon-based materials as supercapacitor electrodes. Chemical Society Reviews, 38(9), 2520-2531.

• [15] Zhao, X., Zhang, L., Murali, S., Stoller, M. D., Zhang, Q., Zhu, Y., & Ruoff, R. S. (2012). Incorporation of manganese dioxide within ultraporous activated graphene for high-performance electrochemical capacitors. ACS Nano, 6(6), 5404-5412.