Electrochemical evaluation of hierarchical NiCo-LDH nanosheets modified with PANI for quasi-solid-state symmetric supercapacitor

Transition metal-based layered double hydroxides (LDHs) have garnered significant attention as promising functional nanomaterials due to their outstanding electrochemical activity and customizable chemical composition. Despite these advantages, pristine LDHs often suffer from severe particle agglomeration and inherently low electrical conductivity, which limit their overall electrochemical performance. In this study, we synthesized a NiCo-LDH@PANI nanocomposite, combining nickel-cobalt LDHs with polyaniline (PANI), a conducting polymer known for its superior electrical conductivity, mechanical stability, and reversible redox behavior. The incorporation of PANI effectively enhances the overall conductivity and structural integrity of the composite material, thereby addressing the limitations associated with individual LDHs. Electrochemical evaluations were carried out using a two-electrode configuration. The NiCo-LDH@PANI nanocomposite exhibited a remarkable specific capacitance of 306.5 F/g at a current density of 2 A/g, significantly higher than that of the pristine LDH electrode. This enhancement is attributed to the excellent rate capability and robust cycling stability of the composite. These improvements stem from the unique architecture of the material, where vertically aligned LDH nanosheets and interlayer cavities provide numerous exposed active sites and facilitate efficient ion transport. Furthermore, the symmetric supercapacitor device assembled using the NiCo-LDH@PANI electrode demonstrated a promising energy density of 61.3 Wh/kg and a power density of 981 W/kg, highlighting its potential for high-performance energy storage applications. The impressive electrochemical behavior of the NiCo-LDH@PANI composite is largely credited to the structural synergy between the LDH layers and polyaniline, which together contribute to enhanced conductivity, mechanical resilience, and redox activity. These findings offer valuable insights into the design and development of advanced electrode materials with high energy and power densities for next-generation supercapacitors.

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