Muhammad Hafidz Ramadhan, Sumari Sumari, Aman Santoso, Adilah Aliyatulmuna
A greater focus on the development of sustainable and renewable energy storage systems is necessary. The advantages of supercapacitors make them promising devices for energy storage technology. However, their low energy density compared to batteries necessitates the design of new electrode materials to enhance their performance. In this study, a binder-free electrode material based on a MnO2@NiMn-LDH composite was synthesized for a symmetric supercapacitor, followed by its characterization and a study of its charge storage mechanism. The stages of this research included (1) Ni-Foam Preparation, (2) MnO2 Synthesis, (3) NiMn-LDH Synthesis, (4) MnO2@NiMn-LDH Composite Synthesis, (5) Material characterization using Powder XRD, FT-IR, SEM, and BET, and (6) Electrochemical testing and charge storage mechanism studies using CV and GCD instruments. Based on this research, a hydrothermal method was successfully used to synthesize δ-MnO2, NiMn-LDH, and the MnO2@NiMn-LDH composite, supported by Powder XRD, SEM, BET, and FT-IR characterization. The specific capacitance of the MnO2@NiMn-LDH composite material was the highest, at 297.08 F g−1 at 5 mV s−1. GCD analysis showed that the symmetric supercapacitor has high cycling stability over 30 cycles, with a coulombic efficiency reaching 100% from the 6th cycle onwards. The energy density and power density of the symmetric supercapacitor were 13.55 Wh kg−1 and 302.03 W kg−1, respectively, at 0.1 A g−1. Furthermore, the analysis of the charge storage mechanism showed that at a low scan rate (5 mV s−1), the diffusion contribution reached 70.6%, which then decreased as the scan rate increased, reaching 50.8% at a scan rate of 50 mV s−1. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2026.
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Jl. Semarang 5, Malang, 65145, Indonesia
