A comparative study on exploring sputtered titanium nitride thin films for high-performance supercapacitors

Abstract

Magnetron sputtered titanium nitride (TiN) thin films possessed desirable electrochemical and physical characteristics making them attractive candidates for supercapacitor electrodes. Herein, the electrochemical performance of TiN films prepared via direct and reactive sputtering methods is investigated as electrodes for supercapacitor. Microstructural analysis revealed distinct morphologies, topographies, and crystal structures for each film type, with reactively sputtered TiN (RS) displaying a pyramidal structure indicative of (111) orientation, whereas directly sputtered TiN (DS) exhibited a granular structure. Electrochemical techniques like cyclic voltammetry, galvanic charge-discharge, and electrochemical impedance spectroscopy clarified the charge storage mechanisms and capacitance behavior. RS exhibited a quasi-rectangular CV profile with pseudo-capacitive behavior with low charge transfer resistance and peak specific capacitance of 90 mF cm⁻² along with superior cyclic stability and ion conductivity. Supercapattery configuration was setup to validate those findings using reactive sputtered thin films. It demonstrated enhanced capacitance retention and low charge transfer resistance, highlighting their potential for practical applications in energy storage systems.