High Charge Transfer and Power Density Performance of CNT/PANI@Ag Nanocomposites for Long- Term Flexible Supercapacitor Applications

A carbon nanotube (CNT)/polyaniline (PANI)@silver nanoparticle (AgNP) nanocomposite was synthesized using a scalable spray-coating technique and evaluated for its electrochemical performance. Electrochemical impedance spectroscopy analysis revealed an ultra-low charge transfer resistance (Rct = 1.2 Ω), significantly reducing interfacial losses and enabling rapid charge transfer. Cyclic voltammetry demonstrated a specific capacitance of 350 F g⁻¹ at 5 mV s⁻¹, with ∼43% retention at 100 mV s⁻¹, confirming superior rate capability. Galvanostatic charge-discharge analysis further validated the composite is outstanding power handling, achieving a yield 37.2 F g⁻¹ at 1 mA due to kinetic limitations at higher currents. The composite delivers an ultrahigh power density of >5,000 W kg⁻¹ at 200 mA (80 A g⁻¹), attributed to the AgNP-enhanced conductivity and low Rct (1.2 Ω), enabling rapid charge delivery even under extreme currents. Long-term cycling tests demonstrated 85% capacitance retention after 1000 cycles, highlighting its stability for prolonged applications. The high electrical conductivity of AgNPs reduces resistive losses, while CNTs provide a robust framework that prevents polymer degradation, making CNT/PANI@Ag nanocomposite an ideal candidate for flexible and high-power energy storage applications. This work presents a scalable, high-performance electrode material that successfully balances high power density, mechanical flexibility, and electrochemical stability, making it a promising solution for advanced energy storage technologies.