Research Information System
Journal of Energy Storage, vol.151, 2026 (SCI-Expanded, Scopus)
This study presents a facile hydrothermal synthesis of Mn(OH)2 nanoparticles, exploring the impact of thiourea and rGO on their electrochemical performance for supercapacitor applications. Structural and morphological analyses confirm the successful formation of highly crystalline β-Mn(OH)2 and reveal that thiourea significantly refines particle size, leading to a more uniform, quasi-spherical morphology. Electrochemical analysis in a three-electrode system reveals prominent redox peaks and a significant current response, indicative of battery-type behavior. The thiourea-assisted Mn(OH)2 electrode exhibits a superior specific capacity of 240 mA h g−1 at 4 mA cm−2, attributed to enhanced active site accessibility and charge transfer kinetics. However, it shows limited cycling stability (13% retention after 3000 cycles). In contrast, the Mn(OH)2-Thiourea-rGO composite, while having a slightly lower initial specific capacity (77 mA h g−1), achieves remarkable long-term stability, retaining 94% of its capacity after 3000 cycles. This improved stability stems from rGO's role as a robust, conductive scaffold that mitigates structural degradation and enhances electron transport. A symmetric supercapacitor constructed with the Mn(OH)2-Thiourea-rGO material delivers an energy density of 12 Wh·kg−1 at a power density of 191 W·kg−1, maintaining a 63% capacitance after 3000 cycles with 98% Coulombic efficiency.