3D Nanostructured Electrodes Based on Anodic Alumina Templates for Stable Pseudocapacitors

Abstract

This study investigates the preparation of nickel nanostructured electrodes for the enhancement of supercapacitor performance. The nanostructured electrodes are synthesized using nanoporous anodic alumina (NAA) as a template via the pulsed electrodeposition method. Structural properties are examined using field-emission scanning electron microscopy, while electrochemical characterization is conducted through cyclic voltammetry (CV) and electrochemical impedance spectroscopy. The results reveal that Ni nanorod arrays can be obtained embedded in the NAA matrix and with electrical contact with the aluminum substrate. On average, the rods are spaced 90 nm apart, with a diameter of 70 nm and a length of 2 μm. The Ni@NAA electrode exhibits an enlarged active area and exceptional electrochemical performance, demonstrating remarkable stability over 5000 cycles of CV at a scan rate of 50 mV s−1. Specific capacitance values exceeding 100 mF cm−2 and maximum charging times of less than 10 min are reported, highlighting its suitability for high-power energy devices requiring pseudo-supercapacitance. The study underscores the significance of nanostructured electrodes in advancing energy storage technologies and presents promising prospects for practical applications.