A study on the performance of lead ferrocyanide-based electrochemical capacitor in RC circuit for low-pass filter application

Abstract Tris-hydroxymethyl aminomethane stabilized ultra-fine lead ferrocyanide particles were synthesized via a complexation-mediated approach and explored the organic–inorganic hybrid system as an electrode material for electrochemical capacitor application. Structural and microscopic characterization confirmed the formation of a crystalline framework of Pb-Fe-C≡N, exhibiting a homogeneous distribution of nanoparticles with sizes ranging from 2 to 6 nm. In a three-electrode setup, the use of lead ferrocyanide as the working electrode demonstrated a high specific capacity of 795 C.g ⁻¹ at a current density of 4 A.g ⁻¹ , along with excellent cycling stability, retaining 93% of its capacity after 5000 charge–discharge cycles. For a symmetric device, lead ferrocyanide based electrodes exhibited a maximum specific capacity of 318 C.g ⁻¹ at 0.5 A.g ⁻¹ and delivered a maximum energy and power density of 97.0 Wh.kg ⁻¹ and 5.5 kW.kg ⁻¹ , respectively, while retained 90% of its initial capacity after 5000 cycles. This assembled device was integrated into a resistor-capacitor circuit as a functional low-pass filter, achieving 69% amplitude attenuation at the cut-off frequency. The findings of this study demonstrate that the lead ferrocyanide-based material delivers outstanding energy storage performance and proves as an effective device in advanced electronic applications, particularly for signal-processing functionalities.