Enhanced electrochemical performance of NiMn layered double hydroxides/graphene oxide composites synthesized by one-step hydrothermal method for supercapacitors.

ABSTRACT

This study aims to enhance the performance of supercapacitors, focusing particularly on optimizing electrode materials. While pure NiMn layered double hydroxides (LDHs) exhibit excellent electrochemical properties, they have limitations in achieving high specific capacitance. Therefore, this paper successfully synthesized composite materials of NiMn LDHs with varying loadings of graphene oxide (GO) using a hydrothermal method. Systematic physicochemical characterization of the synthesized materials, such as powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), and Raman spectroscopy, revealed the influence of GO doping on the microstructure and electrochemical performance of NiMn LDHs. Electrochemical tests demonstrated that the NiMn LDHs/GO electrode material exhibited optimal electrochemical performance with a specific capacitance of 2096 F g-1 at 1 A g-1 current density and 1471 F g-1 at 10 A g-1, when GO doping level was 0.45 wt%. Furthermore, after 1000 cycles of stability testing, the material retained 53.3% capacitance at 5 A g-1, indicating good cyclic stability. This study not only provides new directions for research on supercapacitor electrode materials but also offers new strategies for developing low-cost and efficient electrode materials.